AU2023283201A1 - Cartridge and image forming device - Google Patents
Cartridge and image forming device Download PDFInfo
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- AU2023283201A1 AU2023283201A1 AU2023283201A AU2023283201A AU2023283201A1 AU 2023283201 A1 AU2023283201 A1 AU 2023283201A1 AU 2023283201 A AU2023283201 A AU 2023283201A AU 2023283201 A AU2023283201 A AU 2023283201A AU 2023283201 A1 AU2023283201 A1 AU 2023283201A1
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- developing
- frame
- holding
- force receiving
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Abstract
[Problem] To further develop the prior art. [Solution] This cartridge comprises a first unit, a second unit, a holding unit, and a contact force receiving unit. The contact force receiving unit can be positioned in a waiting position, a first operation position, and a second operation position. From a state in which the second unit is in a distant position, the holding unit is in a first position, and the contact force receiving unit is in the first operation position, the holding unit moves from the first position to a second position by the contact force receiving unit receiving a contact force and moving in a predetermined direction to the second operation position.
Description
[0001] The disclosure relates to a cartridge detachably mountable to an image
forming apparatus such as a copying machine or a printer which uses an
electrophotographic process, and the image forming apparatus provided with the
cartridge.
[0002] Here, the electrophotographic image forming apparatus (hereinafter,
also referred to as "image forming apparatus") is an apparatus which forms an
image on a sheet-like recording material such as paper using an
electrophotographic image forming process. Examples of the image forming
apparatus include a copying machine, a facsimile machine, a printer (laser beam
printer, LED printer, and so on, a multifunction printer thereof, and the like).
[0003] The cartridge is a unit which can be mounted to and dismounted from
the image forming apparatus described above, and is a unit including a
photosensitive member and/or a process means (a charging member, a developing
member, a cleaning member, and so on, for example) which is actable on the
photosensitive member.
[0004] An image forming apparatus which uses an electrophotographic image
forming process includes an image forming apparatus which forms an image by a
contact developing method which forms an image by performing a developing process in a state in which a developing member (developing roller) is in contact with a photosensitive drum. In such an image forming apparatus, the developing roller is urged toward the photosensitive drum at a predetermined pressure, and is in contact with the surface of the photosensitive drum at a predetermined pressure, during the development process.
[0005] In the case that a developing roller including an elastic layer on the
surface is used, the following can be considered, for example. That is, if the
period during which the image is not formed (the developing roller is not
rotating) with the elastic layer kept in contact with the surface of the
photosensitive drum is long, the elastic layer of the developing roller is may be
deformed by the contact with the surface of the photosensitive drum. By this,
image defects such as unintended unevenness of the developer image may occur
when the developing process is performed.
[0006] Further, as another example, when the developing roller is in contact
with the photosensitive drum during the period when the developing process is
not performed, the developer carried on the developing roller is unnecessarily
deposited to the photosensitive drum, and such a developer is deposited on the
recording material with the result of contamination of the recording material.
This problem may occur irrespective of the provision of an elastic layer on the
surface of the developing roller.
[0007] Further, as another example, when the photosensitive drum and the
developing roller are in contact with each other for a long period of time other
than the period during which the developing process is performed, the
photosensitive drum and the developing roller are rubbed against each other for a
long period of time. Deterioration of the developing roller or the developer may
be accelerated. This may occur with or without an elastic layer on the surface of
the developing roller.
[0008] In order to avoid the above-mentioned problem, JP-A-2007-213024
and JP-A-2014-67005 discloses an image forming apparatus and a cartridge
having a structure for spacing a developing roller from a surface of a
photosensitive drum during a period in which developing process is not
performed.
[0009] However, there is still room for further improvement in the
conventional techniques described in Patent Documents. Therefore, it is an
object of the present disclosure to further develop the conventional technique.
[0010] According to a first aspect of the present invention, there is provided a
cartridge comprising a first unit including a photosensitive member, and a first
frame rotatably supporting the photosensitive member; a second unit including a
developing member for depositing toner onto the photosensitive member, and a
second frame rotatably supporting the developing member, wherein the second
unit is movable relative to the first unit between a developing position in which
toner can be deposited onto the photosensitive member from the developing
member, and a separated position in which at least a part of the developing
member is spaced from the photosensitive member; a holding portion, movably
supported by the first unit or the second unit, for restricting a relative position
between the first unit and the second unit, wherein the holding portion is movable
between a first position for holding the second unit at the separated position by
the first unit and a second position for holding the second unit at the developing
position by the first unit; and a contact force receiving portion movably supported
by the first frame or the second frame and capable of receiving a contact force for moving the holding portion from the first position toward the second position to move the second unit to the developing position when the second unit is at the separated position, wherein the contact force receiving portion is capable of taking, by moving relative to the second frame in a predetermined direction, (i) a stand-by position, (ii) a first operating position more outward beyond the second frame than in the stand-by position, and (iii) a second operating position which is more outward beyond the second frame than in the stand-by position and which is different from the first operating position with respect to the predetermined direction, and wherein the holding portion is moved from the first position to the second position, by the contact force receiving portion receiving the contact force and moving to the second operating position in the predetermined direction, in a state in which the second unit is in the separated position, the holding portion is in the first position, and the contact force receiving portion is in the first operating position.
[0011] According to a second aspect of the present invention, there is provided
a cartridge comprising a first unit including a photosensitive member, and a first
frame rotatably supporting the photosensitive member; a second unit including a
developing member for depositing toner onto the photosensitive member, and a
second frame rotatably supporting the developing member, wherein the second
unit is movable relative to the first unit between a developing position in which
toner can be deposited onto the photosensitive member from the developing
member, and a separated position in which at least a part of the developing
member is spaced from the photosensitive member; a holding portion, movably
supported by the first unit or the second unit, for restricting a relative position
between the first unit and the second unit, wherein the holding portion is movable
between a first position for holding the second unit at the separated position by
the first unit and a second position for holding the second unit at the developing position by the first unit; and a separating force receiving portion movably supported by the first frame or the second frame capable of receiving a separating force for moving the holding portion from the second position toward the first position to move the second unit to the separated position when the second unit is at the developing position, wherein the separating force receiving portion is capable of taking, by moving relative to the second frame in a predetermined direction, (i) a stand-by position, (ii) a first operating position more outward beyond the second frame than in the stand-by position, and (iii) a second operating position which is more outward beyond the second frame than in the stand-by position and which is different from the first operating position with respect to the predetermined direction, and wherein the holding portion is moved from the second position to the first position, by the separating force receiving portion receiving the separating force and moving to the first operating position in the predetermined direction, in a state in which the second unit is in the developing position, the holding portion is in the second position, and the separating force receiving portion is in the second operating position.
[0012] According to the present disclosure, the prior art cartridge and so on
can be further developed.
[0013] Figure 1 is a side view of a process cartridge.
[0014] Figure 2 is a sectional view of an image forming apparatus.
[0015] Figure 3 is a sectional view of the process cartridge.
[0016] Figure 4 is a sectional view of the image forming apparatus.
[0017] Figure 5 is a sectional view of the image forming apparatus.
[0018] Figure 6 is a sectional view of the image forming apparatus.
[0019] Figure 7 is a partially enlarged view of a tray.
[0020] Figure 8 is a perspective view of a storing element pressing unit and a
cartridge pressing unit.
[0021] Figure 9 is a perspective view of the image forming apparatus.
[0022] Figure 10 is a side view (partial sectional view) of the process cartridge.
[0023] Figure 11 is a sectional view of the image forming apparatus.
[0024] Figure 12 is a perspective view of a development separation control
unit.
[0025] Figure 13 is an exploded perspective view of the process cartridge.
[0026] Figure 14 is a perspective view of the process cartridge.
[0027] Figure 15 is an exploded perspective view of the process cartridge.
[0028] Figure 16 is an exploded perspective view of the process cartridge.
[0029] Figure 17 illustrates a spacer.
[0030] Figure 18 is an illustration of a movable member.
[0031] Figure 19 is a perspective view of the process cartridge.
[0032] Figure 20 is a partially enlarged view of a side surface of the process
cartridge.
[0033] Figure 21 is a partially enlarged view of the side surface of the process
cartridge.
[0034] Figure 22 is a bottom view of a drive-side of the process cartridge.
[0035] Figure 23 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0036] Figure 24 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0037] Figure 25 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0038] Figure 26 is a side view of the process cartridge in the image forming apparatus main assembly.
[0039] Figure 27 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0040] Figure 28 is an illustration of a spacer.
[0041] Figure 29 is an illustration of a movable member.
[0042] Figure 30 is a perspective view of the process cartridge.
[0043] Figure 31 is a side view (partial sectional view) of the process cartridge.
[0044] Figure 32 is a partially enlarged view of the side surface of the process
cartridge.
[0045] Figure 33 is a partially enlarged view of the side surface of the process
cartridge.
[0046] Figure 34 is a side view (partial sectional view) of the process cartridge.
[0047] Figure 35 is a side view (partial sectional view) of the process cartridge
in the image forming apparatus main assembly.
[0048] Figure 36 is a side view (partial sectional view) of the process cartridge
in the image forming apparatus main assembly.
[0049] Figure 37 is a side view (partial sectional view) of the process cartridge
in the image forming apparatus main assembly.
[0050] Figure 38 is a side view (partial sectional view) of the process cartridge
in the image forming apparatus main assembly.
[0051] Figure 39 is a side view (partial sectional view) of the process cartridge
in the image forming apparatus main assembly.
[0052] Figure 40 is a partially enlarged view of the side surface of the process
cartridge.
[0053] Figure 41 is a partially enlarged view of the side surface of the process
cartridge.
[0054] Figure 42 is a perspective view of a process cartridge and a schematic view illustrating an amount of spacing of a developing roller from a photosensitive drum.
[0055] Figure 43 is a perspective view of the process cartridge and a
schematic view illustrating the amount of spacing of the developing roller from
the photosensitive drum.
[0056] Figure 44 is a perspective view of the process cartridge and a
schematic view illustrating the amount of spacing of the developing roller from
the photosensitive drum.
[0057] Figure 45 is a perspective view of the process cartridge and a
schematic view illustrating the amount of spacing of the developing roller from
the photosensitive drum.
[0058] Figure 46 is a perspective view of the process cartridge and a
schematic view illustrating the amount of spacing of the developing roller from
the photosensitive drum.
[0059] Figure 47 is an illustration of a movable member.
[0060] Figure 48 is an illustration showing a relationship between a movable
member, a spacer, and a non-drive-side bearing.
[0061] Figure 49 is a side view of the process cartridge in the main assembly
of the image forming apparatus and a view illustrating the relationship between
the movable member and the spacer.
[0062] Figure 50 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0063] Figure 51 is a partial perspective view of the process cartridge in the
image forming apparatus main assembly.
[0064] Figure 52 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0065] Figure 53 is a side view of the process cartridge in the main assembly of the image forming apparatus and a view illustrating the relationship between the movable member and the spacer.
[0066] Figure 54 is a perspective view of the developing unit.
[0067] Figure 55 is a perspective view of the process cartridge.
[0068] Figure 56 is a partially enlarged view of a side surface of the process
cartridge.
[0069] Figure 57 is an illustration showing the relationship between the
movable member and the non-drive-side bearing.
[0070] Figure 58 is an illustration of a movable member.
[0071] Figure 59 is an illustration of a movable member.
[0072] Figure 60 is an illustration of operation of the movable member.
[0073] Figure 61 is an illustration of the operation of the movable member.
[0074] Figure 62 is an illustration of the operation of the movable member.
[0075] Figure 63 is an illustration of the operation of the movable member.
[0076] Figure 64 is an illustration of the operation of the movable member.
[0077] Figure 65 is a perspective view of a developing unit portion of the
process cartridge.
[0078] Figure 66 is a perspective view of the process cartridge.
[0079] Figure 67 is an exploded perspective view of a process cartridge.
[0080] Figure 68 is an exploded perspective view of the process cartridge.
[0081] Figure 69 is a side view of the process cartridge.
[0082] Figure 70 is a side view of the process cartridge.
[0083] Figure 71 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0084] Figure 72 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0085] Figure 73 is a side view of the process cartridge.
[0086] Figure 74 is an illustration of mounting of the process cartridge onto a
tray.
[0087] Figure 75 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0088] Figure 76 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0089] Figure 77 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0090] Figure 78 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0091] Figure 79 is a side view of a process cartridge.
[0092] Figure 80 is an exploded perspective view of the process cartridge.
[0093] Figure 81 is an exploded perspective view of the process cartridge.
[0094] Figure 82 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0095] Figure 83 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0096] Figure 84 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0097] Figure 85 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0098] Figure 86 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0099] Figure 87 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0100] Figure 88 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0101] Figure 89 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0102] Figure 90 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0103] Figure 91 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0104] Figure 92 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0105] Figure 93 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0106] Figure 94 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0107] Figure 95 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0108] Figure 96 is a side view of the process cartridge inside the image
forming apparatus main assembly.
[0109] Figure 97 is a side view of the process cartridge inside the image
forming apparatus main assembly.
[0110] Figure 98 is a side view of the process cartridge inside the image
forming apparatus main assembly.
[0111] Figure 99 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0112] Figure 100 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0113] Figure 101 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0114] Figure 102 is an exploded perspective view of a process cartridge.
[0115] Figure 103 is a sectional view of the process cartridge inside an image
forming apparatus main assembly.
[0116] Figure 104 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0117] Figure 105 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0118] Figure 106 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0119] Figure 107 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0120] Figure 108 is an exploded perspective view of a development drive
input gear unit.
[0121] Figure 109 is a sectional view of the development drive input gear unit.
[0122] Figure 110 is a sectional view of the development drive input gear unit.
[0123] Figure 111 is a sectional view of the process cartridge.
[0124] Figure 112 is a perspective view of the process cartridge.
[0125] Figure 113 is a sectional view of the process cartridge.
[0126] Figure 114 is a side view of the process cartridge as viewed along a
lateral direction.
[0127] Figure 115 is a side view of the process cartridge as viewed along the
lateral direction.
[0128] Figure 116 is an exploded perspective view of a process cartridge.
[0129] Figure 117 is an illustration showing a movable member.
[0130] Figure 118 is a perspective view of a development cover member and
the movable member.
[0131] Figure 119 is an illustration of the development cover member and a
separation/contact mechanism.
[0132] Figure 120 is a side view of the process cartridge in the image forming
apparatus main assembly and a side view as seen along the lateral direction.
[0133] Figure 121 is a side view of the process cartridge in the image forming
apparatus main assembly and a side view as seen along the lateral direction.
[0134] Figure 122 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0135] Figure 123 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0136] Figure 124 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0137] Figure 125 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0138] Figure 126 is an exploded perspective view of the process cartridge.
[0139] Figure 127 is a side view of the process cartridge in the image forming
apparatus main assembly as viewed along the lateral direction.
[0140] Figure 128 is a side view of the process cartridge in the image forming
apparatus main assembly as viewed along the lateral direction.
[0141] Figure 129 is a sectional view of the process cartridge.
[0142] Figure 130 is a schematic sectional view of an image forming
apparatus.
[0143] Figure 131 is a schematic sectional view of the process cartridge.
[0144] Figure 132 is an exploded perspective view of the process cartridge.
[0145] Figure 133 is a schematic sectional view of the image forming
apparatus.
[0146] Figure 134 is a schematic sectional view of the image forming
apparatus.
[0147] Figure 135 illustrates a spacer.
[0148] Figure 136 is an exploded perspective view of the process cartridge.
[0149] Figure 137 is a perspective view of the process cartridge.
[0150] Figure 138 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0151] Figure 139 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0152] Figure 140 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0153] Figure 141 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0154] Figure 142 is an illustration of an arrangement of a separation control
member.
[0155] Figure 143 is a sectional view of the process cartridge in the image
forming apparatus main assembly.
[0156] Figure 144 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0157] Figure 145 is an illustration of a drive-side cartridge cover member and
a spacer.
[0158] Figure 146 is an illustration of a positional relationship between a
photosensitive drum and a developing roller.
[0159] Figure 147 is a sectional view of the process cartridge.
[0160] Figure 148 is a sectional view of the process cartridge.
[0161] Figure 149 is a sectional view of the process cartridge in the image
forming apparatus main assembly.
[0162] Figure 150 is an illustration of a driving relationship between a
photosensitive drum and a developing roller.
[0163] Figure 151 is an illustration showing a driving relationship between the photosensitive drum and the developing roller.
[0164] Figure 152 is a sectional view of a process cartridge inside an image forming apparatus main assembly.
[0165] Figure 153 is a sectional view (XX cross-section) of the process cartridge in the main assembly of the image forming apparatus.
[0166] Figure 154 is a sectional view of a process cartridge inside an image forming apparatus main assembly.
[0167] Figure 155 is a sectional view of the process cartridge in the image forming apparatus main assembly.
[0168] Figure 156 is a sectional view of a process cartridge inside an image
forming apparatus main assembly.
[0169] Figure 157 is a sectional view of the process cartridge inside the image forming apparatus main assembly.
[0170] Figure 158 is a perspective view illustrating a drive-side cartridge cover member and a spacer.
[0171] Figure 159 is a sectional view of the process cartridge in the image forming apparatus main assembly.
[0172] Figure 160 is a sectional view of the process cartridge inside the image forming apparatus main assembly.
[0173] Figure 161 is an illustration of a relationship between a movable
member and a spacer.
[0174] Figure 162 is a cross-sectional view of a process cartridge.
[0175] Figure 163 is an illustration of the relationship between the movable member and the spacer.
[0176] Figure 164 is a sectional view of the process cartridge.
[0177] Figure 165 is a side view of a process cartridge.
[0178] Figure 166 is an exploded perspective view of the process cartridge.
[0179] Figure 167 is an exploded perspective view of the process cartridge.
[0180] Figure 168 is a perspective view of a developing side engaging portion.
[0181] Figure 169 is a perspective view of a drum side engaging portion.
[0182] Figure 170 is a perspective view of the process cartridge.
[0183] Figure 171 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0184] Figure 172 is a partial top view of the process cartridge.
[0185] Figure 173 is a perspective view of the process cartridge.
[0186] Figure 174 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0187] Figure 175 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0188] Figure 176 is a partial top view of the process cartridge.
[0189] Figure 177 is a perspective view of the process cartridge.
[0190] Figure 178 is a side view of the process cartridge in the image forming
apparatus main assembly.
[0191] Figure 179 is a sectional view of a process cartridge inside an image
forming apparatus main assembly.
[0192] Figure 180 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0193] Figure 181 is a perspective view of a drive-side cartridge cover.
[0194] Figure 182 is a sectional view of a process cartridge in an image
forming apparatus main assembly.
[0195] Figure 183 is a sectional view of a process cartridge inside an image
forming apparatus main assembly.
[0196] Figure 184 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0197] Figure 185 is a sectional view of the process cartridge in the image
forming apparatus main assembly.
[0198] Figure 186 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0199] Figure 187 is a cross-sectional view of the process cartridge inside the
image forming apparatus main assembly.
[0200] Figure 188 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0201] Figure 189 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0202] Figure 190 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0203] Figure 191 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0204] Figure 192 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0205] Figure 193 is an illustration of an operation of an urging member.
[0206] Figure 194 is a sectional view of a process cartridge inside an image
forming apparatus main assembly.
[0207] Figure 195 is a sectional view of a process cartridge inside an image
forming apparatus main assembly.
[0208] Figure 196 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0209] Figure 197 is a sectional view of a process cartridge inside an image
forming apparatus main assembly.
[0210] Figure 198 is a cross-sectional view of the process cartridge inside the
image forming apparatus main assembly.
[0211] Figure 199 is a cross-sectional view of the process cartridge inside the
image forming apparatus main assembly.
[0212] Figure 200 is a sectional view of the process cartridge inside the image
forming apparatus main assembly.
[0213] Figure 201 is an illustration of an operation of a holding member.
[0214] Figure 202 is an illustration of the operation of the holding member.
[0215] Figure 203 is an illustration showing the operation of the holding
member.
[0216] Figure 204 is a partial perspective view of the process cartridge and a
tray.
[0217] Figure 205 is a partial perspective view of the process cartridge and the
tray.
[0218] Figure 206 is a perspective view of the tray.
[0219] Figure 207 is a sectional view of the process cartridge.
[0220] Figure 208 is a cross-sectional view of a process cartridge inside an
image forming apparatus main assembly.
[0221] Figure 209 is a cross-sectional view of a process cartridge inside an
image forming apparatus main assembly.
[0222] Figure 210 is an illustration showing a relationship between a force
receiving portion of the process cartridge and a separation control member.
[0223] Figure 211 is a sectional view of the process cartridge in the image
forming apparatus main assembly.
[0224] Figure 212 is an illustration showing a relationship between the force
receiving portion of the process cartridge and the separation control member.
[0225] Figure 213 is an illustration showing the relationship between the force
receiving portion of the process cartridge and the separation control member.
[0226] Figure 214 is an illustration showing the relationship between the force receiving portion of the process cartridge and the separation control member.
[0227] Figure 215 is a perspective view of a tray.
[0228] Figure 216 is a perspective view of the tray.
[0229] Figure 217 is an exploded perspective view of a process cartridge.
[0230] Figure 218 is an exploded perspective view of the process cartridge.
[0231] Figure 219 is a perspective view of the process cartridge.
[0232] Figure 220 is a perspective view of the process cartridge.
[0233] Figure 221 is an illustration of an operation of mounting the
developing cartridge on the tray.
[0234] Figure 222 is an illustration of an operation of mounting the
developing cartridge on the tray.
[0235] Figure 223 is a perspective view of the tray on which the developing
cartridge is mounted.
[0236] Figure 224 is a perspective view of the tray on which the developing
cartridge is mounted.
[0237] Figure 225 is a side view of the tray and the developing cartridge in the
image forming apparatus main assembly.
[0238] Figure 226 is a side view of the developing cartridge in the image
forming apparatus main assembly.
[0239] Figure 227 is a side view of the developing cartridge in the image
forming apparatus main assembly.
[0240] Figure 228 is a side view of the developing cartridge in the image
forming apparatus main assembly.
[0241] Figure 229 is a side view of the developing cartridge in the image
forming apparatus main assembly.
[0242] Figure 230 is an illustration of an operation of mounting a drum
cartridge and the developing cartridge on the tray.
[0243] Figure 231 is an illustration of an operation of mounting the drum
cartridge and the developing cartridge on the tray.
[0244] Figure 232 is an illustration showing an operation of mounting the
drum cartridge and the developing cartridge on the tray.
[0245] Figure 233 is a side view of the tray on which the drum cartridge and
the developing cartridge are mounted.
[0246] Figure 234 is a side view of a tray on which the drum cartridge and the
developing cartridge are mounted.
[0247] Figure 235 is a side view (partial sectional view) of the process
cartridge.
[0248] Figure 236 is a schematic sectional view of the process cartridge.
[0249] Figure 237 is a schematic sectional view of the process cartridge.
[0250] Figure 238 is a schematic sectional view of the process cartridge.
[0251] Figure 239 is a schematic sectional view of the process cartridge.
[0252] Figure 240 is a schematic sectional view of the process cartridge.
[0253] Figure 241 is a schematic sectional view of the process cartridge.
[0254] Figure 242 is a side view of the developing cartridge in the image
forming apparatus main assembly.
[0255] Figure 243 is a side view of the developing cartridge in the image
forming apparatus main assembly.
[0256] Figure 244 is a side view of the developing cartridge in the image
forming apparatus main assembly.
[0257] Figure 245 is a side view of the developing cartridge in the image
forming apparatus main assembly.
[0258] Figure 246 is a perspective view illustrating a process cartridge
according to Embodiment 27.
[0259] Figure 247 is an exploded perspective view illustrating a non-drive side of the process cartridge.
[0260] Figure 248 is a perspective view illustrating the non-drive side of the
process cartridge.
[0261] Figure 249 is a front view illustrating the non-drive side of the process
cartridge.
[0262] Figure 250 is a cross-sectional view illustrating the non-drive side of
the process cartridge.
[0263] Figure 251 is a perspective view illustrating a pressing unit assembled
to a non-drive-side bearing.
[0264] Figure 252 is a cross-sectional view illustrating the non-drive-side
bearing and the pressing unit.
[0265] Figure 253 is a sectional view illustrating a state in which the process
cartridge is mounted on the tray.
[0266] Figure 254 is an enlarged cross-sectional view illustrating the pressing
unit.
[0267] Figure 255 is a perspective view illustrating a process cartridge and a
cartridge pressing unit according to Embodiment 28.
[0268] Figure 256 is a cross-sectional view illustrating the process cartridge.
[0269] Figure 257 is a perspective view illustrating the process cartridge and a
cartridge pressing unit.
[0270] Figure 258 is a cross-sectional view illustrating the process cartridge.
[0271] Figure 259 is a perspective view illustrating a process cartridge and a
cartridge pressing unit according to Embodiment 29.
[0272] Figure 260 is a cross-sectional view illustrating the process cartridge.
[0273] Figure 261 is a perspective view illustrating the process cartridge and
the cartridge pressing unit.
[0274] Figure 262 is a perspective view illustrating a process cartridge and a cartridge pressing unit according to Embodiment 29.
[0275] Figure 263 is a view illustrating a drive side of a developing unit
according to Example 30.
[0276] Figure 264 is a perspective view illustrating a drive-side cartridge
cover member, a developing cover member, a moving member, and a link unit.
[0277] Figure 265 is a perspective view illustrating the developing cover
member and the moving member.
[0278] Figure 266 is a perspective view illustrating the developing cover
member.
[0279] Figure 267 is a perspective view illustrating the moving member.
[0280] Figure 268 is a side view illustrating the developing cover member.
[0281] Figure 269 is a perspective view illustrating the drive-side cartridge
cover member, the link unit, and the cam unit.
[0282] Figure 270 is a perspective view illustrating the drive-side cartridge
cover member.
[0283] Figure 271 is an enlarged perspective view illustrating a broken line
portion in part (b) of Figure 270.
[0284] Figure 272 is a view illustrating a link cam and a stopper.
[0285] Figure 273 is an exploded perspective view illustrating a cam unit.
[0286] Figure 274 is an exploded perspective view illustrating the cam unit.
[0287] Figure 275 is a sectional view illustrating the cam unit.
[0288] Figure 276 is a perspective view illustrating the cam unit.
[0289] Figure 277 is a cross-sectional view illustrating the link unit and the
cam unit when the developing unit is located at the contact position.
[0290] Figure 278 is cross-sectional views illustrating the link unit and the
cam unit immediately before the developing unit starts to move from the contact
position to the separation position.
[0291] Figure 279 is cross-sectional views illustrating the link unit and the
cam unit when the developing unit is in the separated position.
[0292] Figure 280 is cross-sectional views illustrating the link unit and the
cam unit immediately before the developing unit starts to move from the
separation position to the contact position.
[0293] Figure 281 is a perspective view illustrating a holding member and a
separation spring of the process cartridge according to Embodiment 31.
[0294] Figure 282 is a cross-sectional view taken along a line 265A-265A of
Figure 281.
[0295] Figure 283 is an exploded perspective view illustrating a drive-side
cartridge cover member, a developing cover member, a holding member, and a
separation spring.
[0296] Figure 284 is an exploded perspective view illustrating the drive-side
cartridge cover member, the developing cover member, the holding member, and
the separation spring.
[0297] Figure 285 is a side view illustrating a force acting on the holding
member.
[0298] Figure 286 is a side view illustrating a force applied on the holding
member.
[0299] Figure 287 is an exploded perspective view illustrating a delaying
mechanism.
[0300] Figure 288 is an exploded perspective view illustrating the delaying
mechanism.
[0301] Figure 289 is a sectional view illustrating a delaying mechanism.
[0302] Figure 290 is a perspective view illustrating the delaying mechanism in
a state in which no drive is input to the developing coupling portion.
[0303] Figure 291 is a perspective view illustrating the delaying mechanism in a drive transmission state.
[0304] Figure 292 is a perspective view illustrating an arrangement
relationship between the lever, the drive-side cartridge cover member, and the
developing cover member.
[0305] Figure 293 is a perspective view illustrating the position of the lever.
[0306] Figure 294 is an illustration of the operation of the delaying
mechanism.
[0307] Figure 295 is an illustration of the operation of the delaying
mechanism.
[0308] Figure 296 is an illustration of the operation of the delaying
mechanism.
[0309] Figure 297 is perspective views illustrating a process cartridge and a separation/contact mechanism according to Embodiment 32.
[0310] Figure 298 is an exploded perspective view illustrating the separation/contact mechanism.
[0311] Figure 299 is cross-sectional views illustrating the separation/contact mechanism.
[0312] Figure 300 is perspective views illustrating a development cover member.
[0313] Figure 301 is perspective views illustrating a holding member.
[0314] Figure 302 is perspective views illustrating a drive side bearing and a pressed member.
[0315] Figure 303 is perspective views illustrating a stepped gear.
[0316] Figure 304 is an illustration of a method of assembling the separation/contact mechanism.
[0317] Figure 305 is an illustration of a method of assembling the separation/contact mechanism.
[0318] Figure 306 is a view illustrating the method of assembling the separation/contact mechanism.
[0319] Figure 307 is an illustration of the method of assembling the separation/contact mechanism.
[0320] Figure 308 is an illustration of the method of assembling the separation/contact mechanism.
[0321] Figure 309 is an illustration of the method of assembling the separation/contact mechanism.
[0322] Figure 310 is a side view and a cross-sectional view illustrating the separation/contact mechanism.
[0323] Figure 311 is an illustration of operation of the separation/contact mechanism.
[0324] Figure 312 is an exploded perspective view illustrating the process cartridge.
[0325] Figure 313 is an illustration of the drive side cartridge cover member.
[0326] Figure 314 is an illustration of a structure of an image forming apparatus main assembly side.
[0327] Figure 315 shows a separation control member.
[0328] Figure 316 is a perspective view illustrating a cartridge pressing mechanism and a separation/contact mechanism.
[0329] Figure 317 is an illustration of the separation/contact mechanism.
[0330] Figure 318 is an illustration of the operation of the separation/contact mechanism.
[0331] Figure 319 is an illustration of the operation of the separation/contact mechanism.
[0332] Figure 320 is an illustration of the operation of the separation/contact mechanism.
[0333] Figure 321 is an illustration of the operation of the separation/contact mechanism.
[0334] Figure 322 is an illustration of the operation of the separation/contact mechanism.
[0335] Figure 323 is an illustration of the operation of the separation/contact mechanism.
[0336] Figure 324 is an illustration of the operation of the separation/contact mechanism.
[0337] Figure 325 is an illustration of the operation of the separation/contact mechanism.
[0338] Figure 326 is an illustration of the operation of the separation/contact mechanism.
[0339] Figure 327 is a perspective view illustrating a holding member and a drive side cartridge cover member according to Embodiment 33.
[0340] Figure 328 is an illustration of the operation of the separation/contact mechanism.
[0341] Figure 329 is an illustration of the operation of the separation/contact mechanism.
[0342] Figure 330 shows a separation control member.
[0343] Figure 331 is an illustration of the operation of the separation/contact mechanism.
[0344] Figure 332 is an illustration of the operation of the separation/contact mechanism.
[0345] Figure 333 is an illustration of the operation of the separation/contact mechanism.
[0346] Figure 334 is an illustration of the operation of the separation/contact mechanism.
[0347] Figure 335 is an illustration of the operation of the separation/contact mechanism.
[0348] Figure 336 is an illustration of the operation of the separation/contact mechanism.
[0349] Figure 337 is an illustration of the operation of the separation/contact mechanism.
[0350] Figure 338 is an illustration of the operation of the separation/contact mechanism.
[0351] Figure 339 is an illustration of the operation of the separation/contact mechanism.
[0352] Figure 340 is an illustration of the operation of the separation/contact mechanism.
[0353] Figure 341 is a perspective view illustrating a drive side cartridge cover member according to a modified example of Embodiment 33.
[0354] Figure 342 is an illustration of the operation of the separation/contact mechanism.
[0355] Figure 343 is an illustration of the operation of the separation/contact mechanism.
[0356] In the following, examples in this disclosure will be described. The
structures disclosed in the following examples, namely the functions, materials,
shapes of parts, and their relative arrangements are examples of the structures
related to the scope of claims, and it is not intended to limit the present invention
to the structure disclosed in the examples. In addition, the problem solved by
the structure disclosed in the following examples or the function or effect
provided by the disclosed structure is not intended to limit the scope of claims.
<Embodiment 1>
[0357] In the following, Embodiment 1 will be described in conjunction with
the accompanying drawings. In the following embodiment, a laser beam printer
which four process cartridges (cartridges) can be mounted to and dismounted
from is illustrated as an image forming apparatus. The number of process
cartridges mounted in the image forming apparatus is not limited to this example.
It may be selected as appropriate if necessary.
[Outline of structure of image forming apparatus]
[0358] Figure 2 is a schematic sectional view of the image forming apparatus
M. Figure 3 is a sectional view of the process cartridge 100. The image
forming apparatus M is a four-color full-color laser printer using an
electrophotographic process, and forms a color image on a recording material S.
The image forming apparatus M is a process cartridge type, in which the process
cartridge is dismountably mounted to the image forming apparatus main
assembly (apparatus main assembly) 170 to form a color image on the recording
material S.
[0359] Here, regarding the image forming apparatus M, a side where a front
door 11 is provided is a front surface (front surface), and a side opposite to the
front surface is a back surface (rear side). Further, a right side of the image
forming apparatus M as viewed from the front is referred to as a drive-side, and a
left side is referred to as a non-drive-side. In addition, as the image forming
apparatus M is viewed from the front, a upper side is a upper surface part, and a
lower side is a lower surface part. Figure 2 is a sectional view of the image
forming apparatus M as viewed from the non-drive-side; the front side of the
sheet of the drawing is the non-drive-side of the image forming apparatus M; the
right side of the sheet of the drawing is the front side; and the rear side of the
sheet of the drawing is the drive-side of the image forming apparatus.
[0360] The drive-side of the process cartridge 100 is the side on which the
drum coupling member (photosensitive member coupling member) which will be
described hereinafter is provided with respect to an axial direction of the
photosensitive drum (the axial direction of the rotation axis of the photosensitive
drum). In addition, the drive-side of the process cartridge 100 is the side on
which a development coupling portion 132a, which will be described hereinafter,
is provided with respect to the axis direction of the developing roller
(development member) (the axial direction of the rotation axis of the developing
roller). The axial direction of the photosensitive drum and the axial direction of
the developing roller are parallel with each other, and the longitudinal direction
of the process cartridge 100 is also parallel to these directions.
[0361] The image forming apparatus main assembly 170 is provided with four process cartridges 100 (1O0Y, OOM, 1OOC, 100K), i.e. A first process cartridge
1OY, a second process cartridge 1OOM, a third process cartridge 1OOC, and a
fourth process cartridge 100K. It is arranged substantially horizontally.
[0362] Each of the first to fourth process cartridges 100 (1O0Y, OOM, OOC,
100K) have the same electrophotographic process mechanisms, but the colors of
the developers (hereinafter referred to as toner) are different from each other.
Rotational driving forces are transmitted to the first to fourth process cartridges
100 (1O0Y, lOOM, 1OOC, lOOK) from the drive output portion (details will be
described hereinafter) of the image forming apparatus main assembly 170,
respectively. Further, bias voltages (charging bias, development bias, and so
on) are supplied from the image forming apparatus main assembly 170 to the first
to fourth process cartridges 100 (1O0Y, OOM, OOC, OOK), respectively.
[0363] As shown in Figure 3, each of the first to fourth process cartridges 100
(1OY, lOOM, 1OOC, lOOK) of this embodiment includes a drum unit 108 having
a photosensitive drum 104 and a charging means as a process means acting on the
photosensitive drum 104. Here, the drum unit may have a cleaning means as
well as the charging means as the process means. Further, each of the first to
fourth process cartridges 100 (1O0Y, OOM, 1OOC,lOOK) includes a developing
unit 109 having developing means for developing an electrostatic latent image on
the photosensitive drum 104. The layout of the electrophotographic image
forming apparatus in which a plurality of photosensitive drums are arranged
substantially in line in this manner is sometimes called an in-line layout or a
tandem layout.
[0364] In each of the first to fourth process cartridges 100, the drum unit 108
and the developing unit 109 are coupled with each other. A more specific
structure of the process cartridge will be described hereinafter.
[0365] The first process cartridge 1OOY contains yellow (Y) toner in a developing container 125, and forms a yellow toner image on the surface of the photosensitive drum 104. The second process cartridge 1OOM contains magenta
(M) toner in a developing container 125, and forms a magenta toner image on the
surface of the photosensitive drum 104. The third process cartridge 100C
contains cyan (C) toner in a developing container 125, and forms a cyan toner
image on the surface of the photosensitive drum 104. The fourth process
cartridge lOOK contains black (K) toner in a developing container 125, and forms
a black toner image on the surface of the photosensitive drum 104.
[0366] As shown in Figure 1, a laser scanner unit 14 as an exposure means is
provided above the first to fourth process cartridges 100(OY, OOM, OOC,
lOOK). The laser scanner unit 14 outputs the laser beam U in accordance with
image information. Then, the laser beam U passes through an exposure window
110 of the process cartridge 100 to scan and expose the surface of the
photosensitive drum 104.
[0367] An intermediary transfer unit 12 as a transfer member is provided
below the first to fourth process cartridges 100 (1O0Y, OOM, OOC, OOK).
The intermediary transfer unit 12 includes a drive roller 12e, a turn roller 12c, and
a tension roller 12b, and a flexible transfer belt 12a extended around them. The
lower surface of the photosensitive drum of each of the first to fourth process
cartridges 100(OY, lOOM, 1OOC, lOOK) is in contact with the upper surface of
the transfer belt 12a. The contact portion between them is a primary transfer
portion. Inside the transfer belt 12a, a primary transfer roller 12d is provided so
as to oppose the photosensitive drum 104. A secondary transfer roller 6 is
contacted with the turn roller 12c by way of the transfer belt 12a. The contact
portion between the transfer belt 12a and the secondary transfer roller 6 is a
secondary transfer portion.
[0368] A feeding unit 4 is provided below the intermediary transfer unit 12.
The feeding unit 4 includes a sheet feed tray 4a on which the recording material S
is loaded and accommodated, and a sheet feed roller 4b.
[0369] A fixing device 7 and a sheet discharging device 8 are provided on the
upper left side of the image forming apparatus main assembly 170 in Figure 2.
The upper surface of the image forming apparatus main assembly 170 is a sheet
discharge tray 13. The recording material S is heated and pressed by fixing
means provided in the fixing device 7, so that the toner image is fixed and
discharged to the sheet discharge tray 13.
[Image forming operation]
[0370] The operation for forming a full-color image is as follows. The
photosensitive drum 104 of each of the first to fourth process cartridges 100
(1OY, 1OOM, 1OOC, lOOK) is rotationally driven at a predetermined speed (in the
direction of arrow A in Figure 3). The transfer belt 12a is also rotationally
driven in a forward direction (direction of an arrow C in Figure 2) codirectionally,
at the peripheries, with the rotation of the photosensitive drum at a speed
corresponding to the speed of the photosensitive drum 104.
[0371] The laser scanner unit 14 is also driven. In synchronism with the
drive of the laser scanner unit 14, the charging roller 105 uniformly charges the
surface of the photosensitive drum 104 to a predetermined polarity and potential
in each process cartridge. The laser scanner unit 14 scans and exposes the
surface of each photosensitive drum 104 with laser beam U in accordance with
the image signals of each color. By this, an electrostatic latent image
corresponding to the image signal of the corresponding color is formed on the
surface of each photosensitive drum 104. The formed electrostatic latent image
is developed by a developing roller 106 that is rotationally driven at a
predetermined speed. By the electrophotographic image forming process
operation described above, a yellow toner image corresponding to a yellow component of the full-color image is formed on the photosensitive drum 104 of the first process cartridge 1OY. Then, the toner image is primary-transferred onto the transfer belt 12a.
[0372] Similarly, a magenta color toner image corresponding to a magenta
component of the full color image is formed on the photosensitive drum 104 of
the second process cartridge 100M. Then, the toner image is primary
transferred and superimposed on the yellow toner image already transferred on
the transfer belt 12a. Similarly, a cyan toner image corresponding to a cyan
component of the full-color image is formed on the photosensitive drum 104 of
the third process cartridge 1OOC. Then, the toner image is primary-transferred
and superimposed on the yellow-colored and magenta-colored toner images
already transferred on the transfer belt 12a. Similarly, a black toner image
corresponding to a black component of the full-color image is formed on the
photosensitive drum 104 of the fourth process cartridge OOK. Then, the toner
image is primary-transferred and superimposed on the yellow, magenta, and cyan
toner images already transferred on the transfer belt 12a. In this manner, an
unfixed four-color full-color toner image of yellow, magenta, cyan, and black is
formed on the transfer belt 12a.
[0373] On the other hand, the recording material S is separated and fed one by
one at a predetermined control timing. The recording material S is introduced
into the secondary transfer portion, which is a contact portion between the
secondary transfer roller 6 and the transfer belt 12a, at a predetermined control
timing. By this, in the process of transporting the recording material S toward
the secondary transfer unit, the four-color superimposed toner image on the
transfer belt 12a is sequentially and collectively transferred onto the surface of
the recording material S. Thereafter, the recording material S is fed to the fixing
device 7 to fix the toner image on the recording material S, and then is discharged onto the sheet discharge tray 13.
[Outline of process cartridge mounting/dismounting structure]
[0374] Referring to Figures 1 and 4 to 7, the tray (hereinafter referred to as a
tray) 171 which supports the process cartridge will be described in more detail.
Figure 4 is a sectional view of the image forming apparatus M in which the tray
171 is inside the image forming apparatus main assembly 170 with the front door
11 open. Figure 5 is a sectional view of the image forming apparatus M in a
state where the tray 171 is outside the image forming apparatus main assembly
170 with the front door 11 open and the process cartridge 100 mounted on the
tray. Figure 6 is a sectional view of the image forming apparatus M in a state
where the tray 171 is outside the image forming apparatus main assembly 170
with the front door 11 open and the process cartridge 100 is not mounted on the
tray. Part (a) of Figure 7 is a partial detailed view of the tray 171 as viewed
from the drive-side in the state of Figure 4. Part (b) of Figure 7 is a partial
detailed view of the tray 171 as viewed from the non-drive-side in the state of
Figure 4.
[0375] As shown in Figures 4 and 5, the tray 171 is movable in a direction
indicated by an arrow (pushing direction) and the direction indicated by an arrow
X2 (pulling direction) with respect to the image forming apparatus main
assembly 170. That is, the tray 171 is provided so as to be retractable and
insertable relative to the image forming apparatus main assembly 170, and the
tray 171 is structured to be movable in a substantially horizontal direction in a
state where the image forming apparatus main assembly 170 is installed on a
horizontal surface. Here, the state in which the tray 171 is outside the image
forming apparatus main assembly 170 (the state shown in Figure 5) is referred to
as an outside position. Further, a state in which the tray is inside the image
forming apparatus main assembly 170 with the front door 11 open and the photosensitive drum 104 and the transfer belt 12a being separated from each other (state in Figure 4) is referred to as an inner position.
[0376] Further, the tray 171 includes a mounting portion 171a in which the process cartridge 100 can be dismountably mounted as shown in Figure 6 in the
outer position. Then, each process cartridge 100 mounted on the mounting
portion 171a in the outer position of the tray 171 is supported on the tray 171 by a
drive-side cartridge cover member 116 and a non-drive-side cartridge cover
member 117 as shown in Figure 7. The process cartridge moves into the image
forming apparatus main assembly 170 by the movement of the tray 171 in a state
of being mounted in the mounting portion 171a. At this time, during this
movement, the transfer belt 12a and the photosensitive drum 104 are spaced with
a gap. Therefore, the tray 171 can move the process cartridge 100 into the
image forming apparatus main assembly 170 without the photosensitive drum 04
contacting the transfer belt 12a (details will be described hereinafter).
[0377] As described above, the tray 171 is capable of moving the plurality of process cartridges 100 collectively to a position where image formation is
possible inside the image forming apparatus main assembly 170, and is
collectively moved to the outside of the image forming apparatus main assembly
170.
[Positioning of process cartridge]
[0378] More specifically, referring to Figure 7, the positioning of the process cartridge 100 with respect to the image forming apparatus main assembly 170
will be described. As shown in Figure 7, the tray 171 is provided with
positioning portions 171VR and 171VL for holding the cartridge 100,
respectively. The positioning portion 171VR has straight portions 171VR1 and
171VR2, respectively. The center of the photosensitive drum is determined by
arc portions 116VR1 and 116VR2 of the cartridge cover member 116 shown in
Figure 7 contacting to the straight portions 171VR1 and 171VR2. Further, the
tray 171 shown in Figure 7 is provided with a rotational direction position setting
projection 171KR. The attitude of the process cartridge 100 is determined with
respect to the apparatus main assembly 170 by the rotational positioning
projection 171KR fitting in the rotational direction position setting recess 116KR
of the cartridge cover member 116 shown in Figure 7.
[0379] The positioning portion 171VL and the rotational direction position
setting projection 171KL are arranged at positions (non-drive-side) opposing
each other across the intermediary transfer belt 12a in the longitudinal direction
of the process cartridge 100 from the positioning portion 171VR. Thatis,onthe
non-drive-side as well, the position of the process cartridge is determined by
engaging the arc portions 117VL1 and 117VL2 of the cartridge cover member
117 with the positioning portion 171VL and the rotational direction position
setting recess 117KL with the rotational direction position setting projection
171KL. By doing so, the position of the process cartridge 100 with respect to
the tray 171 is correctly determined.
[0380] As shown in Figure 5, the process cartridge 100 integral with the tray
171 is moved in the direction of the arrow X1 and inserted to the position shown
in Figure 4. Then, by closing the front door 11 in the direction of the arrow R,
the process carriage 100 is pressed by a cartridge pressing mechanism (not
shown) described hereinafter, and is fixed to the image forming apparatus main
assembly 170 together with the tray 171. Further, the transfer belt 12a comes
into contact with the photosensitive member 4 in interrelation with the operation
of the cartridge pressing mechanism. In this state, an image can be formed
(Figure 2).
[0381] In this embodiment, the positioning portion 171VR and the positioning
portion 171VL also function as reinforcements for maintaining stiffness in a pull- out operation of the tray 171, and for this reason, a sheet metal is used, but the present invention is not limited to this example.
[Cartridge pressing mechanism]
[0382] Next, the details of the cartridge pressing mechanism will be described
with reference to part (a) of Figure 8. Part (a) of Figure 8 shows only the
process cartridge 100, the tray 171 and cartridge pressing mechanisms 190 and
191 and the intermediary transfer unit 12 in the state of Figure 4. Part (b) of
Figure 8 shows only the process cartridge 100, the tray 171 and the cartridge
pressing mechanisms and 191 and the intermediary transfer unit 12 in the state of
Figure 2.
[0383] Here, the process cartridge 100 receives a driving force during image
formation, and further receives a reaction force from the primary transfer roller
12d (Figure 2) in the direction of arrow Z1. Therefore, it is necessary to press
the process cartridge in the Z2 direction in order to maintain a stable attitude
during the image forming operation to prevent the process cartridge from
separating from the positioning portions 171VR and 171VL.
[0384] In order to achieve these, in this embodiment, the image forming
apparatus main assembly 170 is provided with cartridge pressing mechanisms
(190, 191). In the cartridge pressing mechanism (190, 191), a storing element
pressing unit 190 works for the non-drive-side, and a cartridge pressing unit 191
works for the drive-side. This will be described in more detail below.
[0385] By closing the front door 11 shown in Figure 4, the storing element
pressing unit 190 and the cartridge pressing unit 191 shown in Figure 8 lowers in
the direction of arrow Z2. The storing element pressing unit 190 mainly
comprises a main assembly side electric contact (not shown) contactable to the
electric contact of the storing element (not shown) provided in the process
cartridge 100. By interrelating with the front door 11 by a link mechanism (not shown), the storing element 140 and the electric contact on the main assembly side can be brought into and out of contact with each other. That is, the contacts are brought into contact with each other by closing the front door 11, and the contacts are disconnected by opening the front door 11.
[0386] By doing so, when the process cartridge 100 moves inside the image
forming apparatus main assembly together with the tray 171, the electric contacts
are not rubbed, and the contacts are retracted from the insertion/removal locus of
the process cartridge 100, by which the tray 171 can be inserted/removed without
hindering by them. The storing element pressing unit 190 also function to press
the process cartridge 100 against the positioning portion 171VR described above.
Further, similarly to the storing element pressing unit 190, the cartridge pressing
unit 191 also lowers in the direction of arrow Z2 in interrelation with the
operation of closing the front door 11 and function to press the process cartridge
100 against the positioning portion 171VL described above. Further, although
the details will be described hereinafter, the cartridge pressing mechanism (190,
191) also functions to push down movable members 152L and 152R of the
process cartridge 100 which will be described hereinafter.
[Drive transmission mechanism]
[0387] Next, referring to Figures 9 and 10 (for convenience, the tray 171 is
omitted), the drive transmission mechanism of the main assembly in this
embodiment will be described. Part (a) of Figure 9 is a perspective view in
which the process cartridge 100 and the tray 171 are omitted in the state of Figure
4 or Figure 5. Part (b) of Figure 9 is a perspective view in which the process
cartridge 100, the front door 11 and the tray 171 are omitted in the state of Figure
1. Figure 10 is aside view of the process cartridge 100 as viewed from the
drive-side.
[0388] As shown in Figure 10, the process cartridge in this embodiment has a development coupling portion (rotational driving force receiving portion) 132a and a drum coupling member (photosensitive member coupling member) 143.
By closing the front door 11 (state of part (b) of Figure 9, the main assembly side
drum drive coupling 180 and the main assembly side development drive coupling
185 for transmitting the driving forces to the process cartridge 100 project in the arrow Y1 direction by a link mechanism (not shown). Further, by opening the
front door 11 (state of part (a) of Figure 9, the drum drive coupling 180 and a
development drive coupling 185 are retracted in the direction of arrow Y2. By
retracting each coupling from the insertion/removal locus of the process cartridge
(X1 direction, X2 direction), the insertion/removal of the tray 171 is not hindered.
[0389] By closing the front door 11 and starting to drive the image forming apparatus main assembly 170, the drum drive coupling 180 described above
engages with the drum coupling member 143. Further, the development drive
coupling 185 on the main assembly side engages with the development coupling
portion 132a to transmit the drive to the process cartridge 100. The drive
transmission to the process cartridge 100 is not limitedly effected at two places as
described above, and a mechanism for inputting the drive only to the drum
coupling to transmit the drive to the developing roller may be provided.
[Intermediary transfer unit structure]
[0390] Next, referring to Figure 9, the intermediary transfer unit 12 of the
image forming apparatus main assembly in this embodiment will be described.
In this embodiment, the intermediary transfer unit 12 is raised in the direction of
arrow R2 by a link mechanism (not shown) by closing the front door 11 to the
position at the time of image formation (the position where the photosensitive
drum 104 and the intermediary transfer belt 12a are in contact with each other).
Further, by opening the front door 11, the intermediary transfer unit 12 lowers in
the direction of arrow RI, and the photosensitive drum 2 and the intermediary transfer belt 12a are spaced from each other. That is, in the state where the process cartridge 100 is set on the tray 171, the photosensitive drum 104 and the intermediary transfer belt 12a are brought into and out of contact with each other by the opening and closing operations of the front door 11.
[0391] The contact/separation operation uses rising and lowering of the
intermediary transfer unit with a rotational locus around the center point PV1
shown in Figure 4. The intermediary transfer belt 12a is driven by receiving a
force from a gear (not shown) arranged coaxially with the center PV1.
Therefore, by setting the above-mentioned position PV1 as the rotation center,
the intermediary transfer unit 12 can be raised and lowered without moving the
gear center. By doing so, it is unnecessary to move the center of the gear, and
the position of the gear can be maintained with high accuracy.
[0392] With the above-described structure, when the process cartridge 100 is
set in the tray 171 and the tray 11 is inserted or removed, the photosensitive drum
104 does not slide on the intermediary transfer belt 12a, and therefore, image
deterioration which may otherwise be caused by the damaged photosensitive
drum 104 and/or the charge memory.
[Development separation control unit]
[0393] Next, referring to Figures 8, 11, and 12, a spacing mechanism of the
image forming apparatus main assembly in this embodiment will be described.
Figure 11 is a sectional view of the image forming apparatus M taken at a drive
side end portion of the process cartridge 100. Figure 12 is a perspective view of
the development separation control unit as viewed obliquely from the top. In
this embodiment, a development separation control unit 195 controls spacing and
contact operations of the developing unit 109 with respect to the photosensitive
drum 104 by engaging with a portion of the developing unit 109. The
development separation control unit 195 is disposed below the image forming apparatus main assembly 170 as shown in Figure 8.
[0394] Specifically, the development separation control unit 195 is arranged
below the development coupling portion 132a and the drum coupling member
143 in the vertical direction (downward in the arrow Z2 direction).
[0395] Further, the development separation control unit 195 is arranged
adjacent each of opposite ends, in the longitudinal direction (Yl, Y2 direction) of
the photosensitive drum, of the intermediary transfer belt 12. That is, the
development separation control unit 195 includes a development separation
control unit 195R on the drive-side and a development separation control unit
195L on the non-drive-side. By arranging the development separation control
unit 195 in dead space of the image forming apparatus main assembly as
described above, the main assembly can be downsized.
[0396] The development separation control unit 195R includes four separation
control members (force applying members) 196R corresponding to the process
cartridge 100 (1O0Y, OOM, OOC, OOK). The four separation control members
have substantially the same shape. The development separation control unit
195R is always fixed to the image forming apparatus main assembly. However,
the separation control member 196R is structured to be movable in the W41 and
W42 directions by a control mechanism (not shown). The directions W41 and
W42 are substantially parallel to an arrangement direction of the process
cartridges set in the image forming apparatus main assembly 170. The detailed
structure will be described hereinafter.
[0397] The development separation control unit 195L has four separation
control members (force applying members) 196L corresponding to the process
cartridge 100 (1O0Y, OOM, OOC, OOK). The four separation control members
have substantially the same shape. The development separation control unit
195L is always fixed to the image forming apparatus main assembly. However, the separation control member 196L is structured to be movable in the W41 and
W42 directions by a control mechanism (not shown). The detailed structure will be described hereinafter.
[0398] Further, in order for the development separation control unit 195 to engage with a portion of the developing unit 109 and control the
separation/contact operation of the developing unit 109, it is necessary that a
portion of a development control unit 196 and a portion of the developing unit are
overlapped in the vertical direction (ZI, Z2 direction). Therefore, after the
process cartridge 100 is inserted in the X1 direction, a portion of the developing
unit (movable member 152 in the case of this embodiment) is required to project
in the vertical direction (Z1, Z2 direction) as described above (details will be
described hereinafter). When a development separation control unit 195 itself is
raised in the same manner as the above-mentioned intermediary transfer unit 12
for the purpose of such engagement, there are problems such as an increase in the
operating force of the interrelated front door 11 and complication of the drive train.
[0399] It is in consideration of these problems, this embodiment employs a method in which the development separation control unit 195 is fixed to the
image forming apparatus main assembly 170, and a portion (movable member
152) of the developing unit 109 is projected downward (Z2) in the image forming
apparatus main assembly 170. Further, as for the mechanism for projecting the
movable member 152, the mechanisms of the storing element pressing unit 190
and the cartridge pressing unit 191 described above are used as they are, and
therefore, there is no problem as described above and no problem of increase in
the cost of the apparatus main assembly can be suppressed.
[0400] The unit of the development separation control unit 195 as a whole is fixed to the image forming apparatus main assembly 170. However, in order to engage with the movable member 152 to operate so that the developing unit 109 is spaced (spaced position, retracted position) and contacted (contact position) relative to the photosensitive drum 104, a portion of the development separation control unit 195 has a movable structure. Details will be described hereinafter.
[Overall structure of process cartridge]
[0401] Referring to Figures 3, 13 and 14T, the structure of the process
cartridge will be described. Figure 13 is an assembly perspective view of the
process cartridge 100 as viewed from the drive-side, which is one end side in the
axial direction of the photosensitive drum 104. Figure 14 is a perspective view
of the process cartridge 100 as viewed from the drive-side.
[0402] In this embodiment, the first to fourth process cartridges 100 (1O0Y,
1OOM, 1OOC, lOOK) may differ in the color of the contained toner, the toner
filling amount, and the control by the image forming apparatus main assembly
170. However, although these four process cartridges may be different in
dimensions and the like, they have the same basic structures and functions, and
can perform the same functions. Therefore, one process cartridge 100 will be
described as a representative in the following.
[0403] The process cartridge 100 includes the photosensitive drum
(photosensitive member) 104 and the process means for acting on the
photosensitive drum 104, respectively. Here, the process means includes the
charging roller 105 as the charging means (charging member) for charging the
photosensitive drum 104, and a developing means (development member as the
developing roller 106 for developing the latent image formed on the
photosensitive drum 104 by depositing toner onto the photosensitive drum 104.
The developing roller 106 carries the toner on the surface thereof. The process
cartridge 100 may be provided further with a cleaning blade, a brush, or the like
which contacts with the photosensitive drum 104, as the cleaning means (cleaning member) for removing residual toner remaining on the surface of the photosensitive drum 104. Further, as a further process means, as the discharging means for removing electric charge from the surface of the photosensitive drum 104, the light guide member such as a light guide or a lens for irradiating the photosensitive drum 104 with light, a light source, or the like may be provided. The process cartridge 100 is divided into a drum unit (first unit) 108 (108Y, 108M, 108C, 108K) and the developing unit (second unit) 109
(109Y, 109M, 109C, 109K).
[Drum unit structure]
[0404] As shown in Figures 3 and 13, the drum unit 108 includes the
photosensitive drum 104, the charging roller 105, a first drum frame portion 115,
a drive-side cartridge cover member 116 and a non-drive-side cartridge cover
member 117 as the second drum frame mounted to the first drum frame portion
115. The photosensitive drum 104 is rotatably supported about the rotation axis
(rotation center) M1 by the drive-side cartridge cover member 116 and the non drive-side cartridge cover member 117 provided at both ends in the longitudinal
direction of the process cartridge 100. The drum frame (first frame) in which
the first drum frame portion 115, the drive-side cartridge cover member 116 and
the non-drive-side cartridge cover member as the second drum frame portion 117
constitutes the drum frame (first frame or second frame) rotatably supporting the
photosensitive drum 104.
[0405] The drive-side cartridge cover member 116 and the non-drive-side cartridge cover member 117 will be described hereinafter. As shown in Figures
13 and 14, a coupling member 143 for transmitting a driving force to the
photosensitive drum 104 is provided on one end side of the photosensitive drum
104 in the longitudinal direction. As described above, the coupling member 143
engages with the main assembly side drum drive coupling (see Figure 9) as a drum drive output portion of the image forming apparatus main assembly 170.
Then, the driving force of the driving motor (not shown) of the image forming
apparatus main assembly 170 is transmitted to the photosensitive drum 104 to
rotate it in a direction of arrow A. Further, the photosensitive drum 104 is
provided with a drum flange 142 on the other end side in the longitudinal
direction. The charging roller 105 is supported by the drum frame 115 in
contact with the photosensitive drum 104 and is driven thereby to rotate. The
rotation axis M1 is parallel to the longitudinal direction of the process cartridge
100 and the longitudinal direction of the drum unit 108.
[Structure of Developing unit]
[0406] As shown in Figures 3 and 13, the developing unit 109 includes the
developing roller 106, a toner feeding roller (developer agent supply member)
107, a developing blade 130, the developing container 125, and so on. The
developing container 125 includes a lower frame 125a and a lid member 125b.
The lower frame 125a and a lid member 125b are connected by ultrasonic
welding or the like. The developing container 125, which is the second frame,
has a toner accommodating portion 129 for accommodating toner to be supplied
to the developing roller 106. A drive-side bearing 126 and a non-drive-side
bearing are mounted and fixed to respective ends of the developing container 125
in the longitudinal direction. The developing container 125 rotatably supports
the developing roller 106, a toner feeding roller 107, and a stirring member 129a
by way of the drive-side bearing and the non-drive-side bearing 127, and holds
the developing blade 130. In this manner, the developing container 125, the
drive-side bearing 126, and the non-drive-side bearing 127 constitute the
developing frame (second frame) that rotatably supports the developing roller 106
about the rotation axis (rotation center) M2.
[0407] The stirring member 129a rotates to stir the toner in the toner accommodating portion 129. The toner feeding roller (developer material supply member) 107 contacts the developing roller 106, supplies toner to the surface of the developing roller 106, and also strips the toner off the surface of the developing roller 106. The developing blade 130 is formed by mounting an elastic member 130b, which is a sheet-like metal including a thickness of about
0.1 mm, to a supporting member 130a, which is a metal material including an L
shaped cross-section, by welding or the like. The developing blade 130
regulates the toner layer thickness (thickness of the toner layer) on the peripheral
surface of the developing roller 106 to form a toner layer having a predetermined
thickness between the elastic member 130b and the developing roller 106. The
developing blade 130 is mounted to the developing container 125 with fixing
screws 130c at two positions in one end side and the other end side in the
longitudinal direction. The developing roller 106 comprises a metal core metal
106c and a rubber portion 106d.
[0408] Further, as shown in Figures 13 and 14, the development coupling
portion 132a for transmitting the driving force to the developing unit 109 is
provided on one end side of the developing unit in the longitudinal direction.
The development coupling portion 132a engages with the development drive
coupling 185 (see Figure 9) on the main assembly side as a development drive
output portion of the image forming apparatus main assembly 170 to receive the
driving force, thereby to rotate the drive motor (not shown) of the image forming
apparatus main assembly 170. The driving force received by the development
coupling portion 132a is transmitted by a driving train (not shown) provided in
the developing unit 109, so that the developing roller 106 can be rotated in the
direction of arrow D in Figure 3. A development cover member 128 which
supports and covers a development coupling portion 132a and a driving train (not
shown) is provided on one end side of the developing unit 109 in the longitudinal direction. An outer diameter of the developing roller 106 is selected to be smaller than the outer diameter of the photosensitive drum 104. The outer diameter of the photosensitive drum 104 in this embodiment is in the range of
D18 to 022 (mm), and the outer diameter of the developing roller 106 is in the
range of (8 to 014 (mm). By selecting the outer diameters in this way, efficient arrangement is accomplished. The rotation axis M2 is parallel to the
longitudinal direction of the process cartridge 100 and to the longitudinal
direction of the developing unit 109.
[Assembly of drum unit and developing unit]
[0409] Referring to Figure 13, the assembly of the drum unit 108 and the
developing unit 109 will be described. The drum unit 108 and the developing
unit 109 are connected by a drive-side cartridge cover member 116 and a non
drive-side cartridge cover member 117 provided at opposite ends in the
longitudinal direction of the process cartridge 100. The drive-side cartridge
cover member 116 provided on one end side of the process cartridge 100 in the longitudinal direction is provided with a developing unit supporting hole 116a for
swinging (moving) of the developing unit 109. Similarly, the non-drive-side
cartridge cover member 117 provided on the other end side of the process
cartridge 100 in the longitudinal direction is provided with a developing unit
supporting hole 117a for swingably supporting the developing unit 109. Further, the drive-side cartridge cover member 116 and the non-drive-side cartridge cover
member 117 are provided with drum supporting holes 116b and 117b for
rotatably supporting the photosensitive drum 104. Here, on one end side, the
outer diameter portion of a cylindrical portion 128b of the development cover
member 128 is fitted into the developing unit supporting hole 116a of the drive
side cartridge cover member 116. On the other end side, the outer diameter
portion of the cylindrical portion (not shown) of the non-drive-side bearing 127 is fitted into the developing unit supporting hole 117a of the non-drive-side cartridge cover member 117. Further, the opposite ends of the photosensitive drum 104 in the longitudinal direction are fitted into the drum supporting holes
116b of the drive-side cartridge cover member 116 and drum supporting holes
117b of the non-drive-side cartridge cover member 117. Thedrive-side
cartridge cover member 116 and the non-drive-side cartridge cover member are
fixed to the drum unit 108 with screws or adhesives (not shown). By this, the
developing unit 109 is rotatably supported by the drive-side cartridge cover
member 116 and the non-drive-side cartridge cover member 117 with respect to
the drum unit 108 (photosensitive drum 104). In such a structure, the
developing roller 106 can be positioned at a place for acting on the photosensitive
drum 104 during image formation.
[0410] Figure 14 shows a state in which the drum unit 108 and the developing
unit 109 are assembled by the above-described steps and integrated into the
process cartridge 100.
[0411] The axis connecting the center of the developing unit supporting hole
116a of the drive-side cartridge cover member 116 and the center of the
developing unit supporting hole 117a of the non-drive-side cartridge cover
member 117 is called a swing axis (rotation axis, rotation center) K. Here,the
cylindrical portion 128b of the development cover member on one end side is
coaxial with the development coupling portion 132a. That is, the rotation axis
of the development coupling portion 132a is coaxial with the swing axis K. In
other words, the swing axis K is also the rotation axis K of the development
coupling portion 132a. Further, the developing unit 109 is supported rotatably
about the swing shaft K. In a state where the drum unit 108 and the developing
unit 109 are assembled and integrated as the process cartridge 100, the rotation
axis M1, the rotation axis M2, and the swing axis K are substantially parallel to each other. Further, in this state, the rotation axis M1, the rotation axis M2, and the swing axis K are substantially parallel to the longitudinal direction of the process cartridge 100, respectively.
[Structure of separation/contact mechanism 150]
[0412] The structure in which the photosensitive drum 104 of the process
cartridge 100 and the developing roller 106 of the developing unit 109 are spaced
(separated) and contacted with each other in this embodiment will be described in
detail. The process cartridge is provided with a separation/contact mechanism
150R on the drive-side and a separation/contact mechanism 150L on the non
drive-side. Figure 15 shows an assembly perspective view of the drive-side of
the developing unit 109 including the separation/contact mechanism 150R.
Figure 16 shows an assembly perspective view of the developing unit including
the separation/contact mechanism 150L on the non-drive-side. Regarding the
separation/contact mechanism, the details of the separation/contact mechanism
150R on the drive-side will first be described, and then the separation/contact
mechanism 150L on the non-drive-side will be described. The
separation/contact mechanism has almost the same functions on the drive-side
and the non-drive-side, and therefore, R is added to the reference numeral of each
member on the drive-side. For the non-drive-side, the reference numeral of each
member is the same as that of the drive-side, and L is added.
[0413] The separation/contact mechanism 150R includes a spacer R (spacer
151R) which is a restriction member (holding member), a movable member 152R
which is a pressing member (force applying member), and a tension spring 153.
The separation/contact mechanism 150L includes a spacer L (spacer 151L) which
is a restricting member, a movable member 152L which is a pressing member
(force applying member), and a tension spring 153.
[Detailed description of spacer 151R]
[0414] Here, the spacer (holding member) 151R will be described in detail
with reference to Figure 17. Part (a) of Figure 17 is a front view of the process
cartridge 100 of the spacer 151R per se as viewed from the drive-side
longitudinal direction. Part (b) of Figure 17 and part (c) of Figure 17 are
perspective views of the spacer 15IR, and part (d) of Figure 17 is a view of the
spacer 151R as viewed in the direction of arrow Z2 in part (a) of Figure 17
(vertically upward in the image forming state). The spacer 151R includes an
annular supported portion 151Ra, and includes a separation holding portion
(holding portion) 151Rb projecting from the supported portion 151Ra in the
radial direction of the supported portion 151Ra. The free end of the separation
holding portion 151Rb includes a contact surface (contact portion)151Rc having
an arc shape centered on the swing axis H of the spacer 151R and having an
inclination of an angle 01 with respect to the line HA substantially parallel to the
swing axis H. The angle 01 is selected so as to satisfy the following inequality
(1):
0° 01 45° .... (1)
[0415] The separation holding portion (holding portion) 151Rb is a portion
which connects the supported portion 151Ra and the contact surface 151Rc, and
is sandwiched between the drum unit 108 and the developing unit 109 and has
sufficient rigidity to maintain the spaced position.
[0416] Further, the spacer 151R has a restricted surface (restricted portion)
15iRk adjacent to the contact surface 151Rc. Further, the spacer 15iR has a
restricted surface (restricted portion) 151Rd projecting in the Z2 direction beyond
the supported portion 151Ra, and has an arc shape pressed surface (at-contact
pressed portion) 151Re projecting from the restricted surface 151Rd in the swing
axis H direction of the supported portion 151Ra.
[0417] Further, the spacer 151R includes a main body portion 151Rf connected to the supported portion 151Ra, and the main body portion 151Rf includes a spring-hooked portion 151Rg projecting in the swing axis H direction of the supported portion 151Ra. Further, the main body portion 151Rf has a rotation prevention portion 151Rm projecting in the Z2 direction, and the rotation prevention surface 151Rn is provided in a direction of opposing the pressed surface 151Re.
[Detailed description of movable member 152R]
[0418] Here, the movable member 152R will be described in detail with
reference to Figure 18. Part (a) of Figure 18 is a front view of the movable
member 152R as viewed in the longitudinal direction of the process cartridge 100,
and Figures 18B and 18C are perspective views of the movable member 152R per
se.
[0419] The movable member 152R has an oblong-shaped oblong supported
portion 152Ra. Here, the longitudinal direction of the oblong shape of the
oblong supported portion 152Ra is indicated by an arrow LH, the upper portion is
indicated by an arrow LH1, and the lower portion is referred to as an arrow LH2.
Further, the direction in which the oblong round supported portion 152Ra is
formed is indicated by HB. The movable member 152R has a projecting portion
(force receiving portion) 152Rh formed on the downstream side in the arrow LH2
direction of the oblong supported portion 152Ra. The oblong supported portion
152Ra and the projecting portion 152Rh are connected by a main body portion
152Rb. On the other hand, the movable member 152R includes a pressed
portion 152Re projecting in the direction of the arrow LH1 direction and the
direction substantially perpendicular to the direction of arrow LH1, an arc-shaped
pressed surface 152Rf (moving force receiving portion, operating force receiving
portion) on the downstream side in the arrow LH1 direction, and a pressing
restricting surface 152Rg on the upstream side. Further, the movable member
152R has a first restricted surface (first restricted portion) 152Rv extending from
the main body portion 152Rb toward the upstream side in the arrow LH2
direction with respect to the projecting portion 152Rh. Further, the movable
member 152R has a second restricted surface 152Rw adjacent to the first
restricted surface 152Rv and substantially parallel to the developing frame
pressing surface (developing frame pressing portion, second frame pressing
portion) 152Rq.
[0420] The projecting portion 152Rh includes a first force receiving portion
(retracting force receiving portion, separating force receiving portion) 152Rk and
a second force receiving portion (contact force receiving portion) 152Rn)
arranged at the end in the arrow LH2 direction and in a direction substantially
perpendicular to the arrow LH2 direction. The first force receiving portion
152Rk and the second force receiving portion 152Rn includes an arc shape first
force receiving surface (retracting force receiving surface and the separating force
receiving surface) 152Rm and a second force receiving surface (contact force
receiving surface 152Rp) extending in the HB direction. Further, the projecting
portion 152Rh has a spring-hooked portion 152Rs projecting in the H direction
and a locking portion 152Rt, and the locking portion 152Rt has a locking surface
152Ru opposing in the same direction as the second force receiving surface
152Rp.
[0421] Further, the movable member 152R is a part of the main body portion
152Rb, is arranged on the upstream side in the arrow LH2 direction with respect
to the second force receiving portion 152Rn, and has a developing frame pressing
surface 152Rq facing the same direction as the second force receiving surface
152Rp. Further, the movable member 152R has a spacer pressing surface
(pressing portion) 152Rr which is perpendicular to the first restricted surface
152Rv and is arranged to oppose the developing frame pressing surface 152Rq.
[0422] When the process cartridge 100 is mounted on the image forming
apparatus main assembly 170, the LH1 direction is substantially the same as the
Z1 direction, and the LH2 direction is substantially the same as the Z2 direction.
Further, the HB direction is substantially the same as the longitudinal direction of
the process cartridge 100.
[Assembly of separation/contact mechanism 150R]
[0423] Referring to Figures 10, 15 to 19, the assembly of the
separation/contact mechanism 150R will be described. Figure 19 is a
perspective view of the process cartridge 100 after assembling the spacer 151R as
viewed from the drive-side.
[0424] As described above, as shown in Figure 15, in the developing unit 109,
the outer diameter portion of the cylindrical portion 128b of the development
cover member 128 is fitted into a developing unit supporting hole portion 116a of
the drive-side cartridge cover member 116. By this, the developing unit 109 is
supported rotatably about the swing axis K relative to the photosensitive drum
104. Further, the development cover member is provided with a cylindrical first
supporting portion 128c and a second supporting portion 128k projecting in the
direction of the swing axis K.
[0425] The outer diameter of the first supporting portion 128c fits with an
inner diameter of the supported portion 151Ra of the spacer 151R, and rotatably
supports the spacer 151R. Here, a swing center of the spacer 151R assembled to
the development cover member 128 is defined as the swing axis H. The
development cover member 128 is provided with a first retaining portion 128d
which projects in the direction of the swing axis H. As shown in Figure 15, the
movement of the spacer 151R assembled to the development cover member 128
in the swing axis H direction is restricted by the contact of the first retaining
portion 128d to the spacer 15IR.
[0426] Further, the outer diameter of the second supporting portion 128k fits
with an inner wall of the oblong supported portion 152Ra of the movable member
152R, and supports the movable member 152R so as to be rotatable and movable
in the length direction of the oblong direction. Here, the swing center of the
movable member 152R assembled to the development cover member 128 is
referred to as a movable member swing axis HC of the movable member. As
shown in Figure 15, the movement of the movable member 152R assembled to
the development cover member 128 in the swing axis HC direction is restricted
by the contact of a second retaining portion 128m to the spacer 151R.
[0427] Figure 10 is a sectional view in which a portion of the drive-side
cartridge cover member 116 and a portion of the development cover member 128
are omitted in a sectional line CS so that the fitting portion between the oblong
supported portion 151Ra of the movable member 152R and the cylindrical
portion 128b of the development cover member 128 can be seen. The
separation/contact mechanism 150R includes the tension spring 153 provided
with a spacer portion urging portion (holding portion urging portion) which urges
the spacer 151R to rotate in the direction of arrow B1 in the drawing about the
swing shaft H, and provided with a force receiving portion urging portion
(projecting portion urging portion) for urging the movable member 152R is in the
B3 direction indicated by an arrow. The tension spring 153 is a coil spring
which is an elastic member. The arrow B3 direction is a direction substantially
parallel to the long circle extending longitudinal direction LH2 (see Figure 18) of
the oblong round supported portion 152Ra of the movable member 152R. The
tension spring 153 is engaged with and connected with the spring-hooked portion
151Rg provided on the spacer 151R and the spring-hooked portion 152Rs
provided on the movable member 152R, and is assembled between them. The
tension spring 153 applies a force to the spring-hooked portion 151Rg of the spacer 151R in the direction of arrow F2 in Figure 10 to apply an urging force to rotate the spacer 151Rin the direction of arrow Bl. Further, the tension spring
153 applies a force to the spring-hooked portion 152Rs of the movable member
152R in the direction of the arrow F1 to move the movable member 152R in the
direction of the arrow B3 (direction toward the accommodating position
(reference position, stand-by position)).
[0428] The line GS is a line connecting the spring-hooked portion 151Rg of
the spacer 151R and a spring-hooked portion 152Rs of the force holding member
152R, and the line HS is a line connecting the spring-hooked portion 152Rs of
the movable member 152R and the movable member swinging axis HC. An
angle 02 formed by the line GS and the line HS is selected so as to satisfy the
following inequality (2) with the clockwise direction centered on the spring
hooked portion 152Rs of the movable member 152R as positive. By this, the
movable member 152R is urged to rotate in the direction of arrow BA with the
movable member swing axis HC as the center of rotation.
0° : 02 90° .... (2)
[0429] As shown in Figure 15, in the development drive input gear
(development coupling member) 132 provided with the development coupling
portion 132a, an inner diameter portion of the cylindrical portion 128b of the
development cover member 128 and an outer circumference of a cylindrical
portion 32b of the development drive input gear 132 are fitted, and in addition, a
support portion 126a of the drive-side bearing 126 and the cylindrical portion (not
shown) of the development drive input gear 132 are fitted. By this, the
development drive input gear 132 is rotatably supported around the rotation axis
K. The developing roller gear 131 is fixed to the drive-side end of the
developing roller 106, and a toner feeding roller gear 133 is fixed to the drive
side end of the toner feeding roller (developer supply member) 107. The development drive input gear (development coupling member) 132 is provided with a gear portion on an outer peripheral surface of the cylinder, and this gear portion meshes with the developing roller gear 131, the toner feeding roller gear
133, and other gears to transmit the received rotational driving force to these
gears.
[0430] In this embodiment, the arrangement of the spacer 15IR and the
movable member 152R in the direction of the swing axis K will be described.
As shown in Figure 15, in the direction of the swing axis K, the spacer 151R is
provided on the side where the drive-side cartridge cover member 116 is disposed
(outside in the longitudinal direction) with respect to with the development cover
member 128, and the movable member 152R is provided on the side (inside in
the longitudinal direction) where the development drive input gear 132 is
disposed. However, the positional arrangement is not limited to this example,
and the positions of the spacer 15IR and the movable member 152R may be
interchanged, or the spacer 151R and the movable member 152R may be
arranged on one side with respect to the development cover member 128 in the
swing axis K direction. Further, the arrangement order of the spacer 151R and
the movable member 152R may be exchanged.
[0431] The development cover member 128 is fixed to the developing
container 125 by way of the drive-side bearing 126 to form the developing unit
109. As shown in Figure 15, the fixing method in this embodiment uses a fixing
screw 145 and an adhesive (not shown), but the fixing method is not limited to
this example, and welding such as welding by heating or pouring and hardening
of resin may be used.
[0432] Here, Figure 20 is a sectional view in which a periphery of the
separation holding portion 151R in Figure 10 is enlarged, and a part of the
tension spring 153 and the spacer 151R is partially omitted on the partial sectional line CS4 for the sake of better illustration. In the movable member
152R, the first restricted surface 152Rv of the movable member 152R comes into
contact with a first restricted surface 128h of the development cover member 128
by the urging force of the tension spring 153 in the Fl direction in the drawing.
Further, the second restricted surface 152Rw of the movable member 152R comes into contact with a second restricted surface 128q of the development
cover member 128 and is positioned. This position is referred to as an
accommodated position for the movable member 152R and the projecting portion
152Rh. The accommodated position can also be referred to as a reference
position or a stand-by position. Further, the spacer 151R is rotated in the BI
direction about the swing axis H by the urging force of the tension spring 153 in
the F2 direction, and the restricted surface 151Rd of the spacer 151R is brought
into contact with the spacer pressing surface 152Rr of the movable member 152R
to stop the rotation. This position is referred to as a separation holding position
(restriction position, first position) of the spacer 151R.
[0433] Further, Figure 21 is an illustration in which the periphery of the separation holding portion 151R in Figure 10 is enlarged, and the tension spring
153 is omitted for better illustration. Here, the case will be considered in which
the process cartridge 100 including the separation/contact mechanism 150R of
this embodiment is dropped in the JA direction in Figure 21 when the process
cartridge 100 is transported. At this time, the spacer 151R receives a force
tending to rotate in the direction of arrow B2 due to its weight around the
separation holding swing shaft H. When the spacer 151R starts to rotate in the
B2 direction for this reason, the rotation prevention surface 151Rn of the spacer
151R comes into contact with the locking surface 152Ru of the movable member
152R, and the spacer 151R receives a force in the F3 direction in the drawing so
as to suppress the rotation in the B2 direction. By this, it is possible to prevent the spacer 151R from rotating in the B2 direction during transportation, and it is possible to prevent the separation state between the photosensitive drum 104 and the developing unit 109 from being broken.
[0434] In this embodiment, the tension spring 153 is used as the urging means
for urging the spacer 151R to the separation holding position and the movable
member 152R to the accommodated position, but the urging means is not limited
to this example. For example, a torsion coil spring, a leaf spring, or the like may
be used as an urging means to urge the movable member 152R to the
accommodated position and the spacer 151R to the separation holding position.
Further, the material of the urging means may be metal, a mold, or the like, if it
has elasticity and can urge the spacer 15IR and the movable member 152R.
[0435] As described above, the developing unit 109 provided with the
separation/contact mechanism 150R is integrally coupled with the drum unit 108
by the drive-side cartridge cover member 116 as described above (state in Figure
19).
[0436] Figure 22 is a view as seen in the direction of arrow J in Figure 19.
As shown in Figure 15, the drive-side cartridge cover member 116 of this
embodiment has a contacted surface (contact portion) 116c. As shown in Figure
22, the contacted surface 116c is formed with an inclination of an angle 03 with
respect to the swing axis K. The angle 03 is preferably the same as the angle 01
forming the contact surface 151Rc of the spacer 15IR, but is not limited to such.
Further, as shown in Figures 15 and 19, the contacted surface 116c is opposed to
the contact surface 151Rc of the spacer 15IR placed at the separation holding
position when the drive-side cartridge cover 116 is assembled to the developing
unit 109 and the drum unit 108. Further, the contacted surface 116c contacts the
contact surface 151Rc by the urging force of the development pressure spring 134
which will be described hereinafter. When the contacted surface 116Rc and the contact surface 151Rc are brought into contact with each other, the attitude of the developing unit 109 is determined so that the developing roller 106 of the developing unit 109 and the photosensitive drum 104 are separated by a gap P.
The state in which the developing roller 106 (developing member) is spaced from
the photosensitive drum 104 by the gap P1 by the spacer 151R is referred to as a
spaced position (retracted position) of the developing unit 109 (see part (a) of
Figure 1).
[Separation state and contact state of process cartridge 100 (drive-side)]
[0437] Referring to Figure 1, the spaced state and the contact state of the
process cartridge 100 will be described in detail. Figure 1 is a side view of the
process cartridge 100 as viewed from the drive-side with the process cartridge
100 mounted inside the image forming apparatus main assembly 170. Part(a)
of Figure 1 shows a state in which the developing unit 109 is separated from the
photosensitive drum 104. Part (b) of Figure 1 shows a state in which the
developing unit 109 is in contact with the photosensitive drum 104.
[0438] First, a state in which the spacer 151R is in the separation holding
position (first position) and the developing unit 109 is in the separation position
(retracted position) will be described. In this state, the supported portion 151Ra
which is one end of the separation holding portion 151Rb contacts the first
supporting portion 128c of the development cover member 128, and the contact
portion 151Rc which is the other end contacts the contacted surface 116c of the
drive-side cartridge cover member 116. Further, the first supporting portion
128c is pressed toward the supported portion 151Ra by the action of the
development pressure spring 134, and the contact portion 151Re is pressed
toward the contacted surface 116c. Therefore, it can be said that this state is a
state in which the drive-side cartridge cover member 116 positions the
development cover member 128 by way of (sandwiching) the separation holding portion 151Rb of the spacer 151R and stably holds the development cover member 128. That is, it can be said that the drum unit 108 is positioned and stably hold it by the developing unit 109 by way of the spacer 151R.
[0439] From this state, the pressed portion 152Re of the movable member
152R is pushed in the ZA direction. By this, the movable member 152R and the
projecting portion 152Rh move linearly from the stand-by position in the ZA
direction (operating direction, predetermined direction) to reach the projecting
position. The ZA direction is parallel to the rotation axis M2 of the developing
roller 106 or the rotation axis M1 of the photosensitive drum 108. Therefore,
the projecting portion 152Rh when in the projecting position is arranged
downstream in the ZA direction from the projecting portion 152Rh when in the
stand-by position. Therefore, the projecting portion 152Rh placed in the
projecting position is located more remote from the swing axis K than the
projecting portion 152Rh placed in the stand-by position. Further, the
projecting portion 152Rh placed at the projecting position projects in the ZA
direction from the drum frame and the developing frame (arranged downstream
in the ZA direction). In this embodiment, as described above, the drum frame
includes the first drum frame portion 115, the drive-side cartridge cover member
116, and the non-drive-side cartridge cover member 117, and the developing
frame includes the developing container 125 and the drive-side bearing 126 and
the non-drive-side bearing 127. The ZA direction is the direction crossing with
the direction in which the four process cartridges 100 are arranged, the W41
direction, and the W42 direction.
[0440] It can be said that the attitude shown in Figure 1 is also the attitude in
which the rotation axis M1 of the photosensitive drum 104 is horizontal and the
photosensitive drum 104 is arranged at the lower portion in the process cartridge
100 when the vertical direction in the Figure is the vertical direction. Inthis attitude, it can be said that the projecting portion 152Rh projects downward by projecting in the ZA direction.
[0441] Further, Figures 26 and 38 show the attitude of the process cartridge
100 in a state of being mounted in the image forming apparatus main assembly
170, and the vertical direction in the drawing is the vertical direction (ZI
direction, Z2 direction) when the image forming apparatus main assembly 170 is
installed on a horizontal surface. The ZA direction vector in this attitude is a
vector including at least a vertical component. Therefore, even in this attitude, it
can be said that the projecting portion 152Rh projects downward by projecting in
the ZA direction.
[0442] The movable member 152R can move in the ZA direction and the
direction opposite thereto while maintaining the state that the spacer 151R is in
the separation holding position (first position). Therefore, even when the
movable member 152R and the projecting portion 152Rh are in the operating
position, the spacer 15IR is located in the separation holding position (first
position). At this time, the pressed surface 151Re of the spacer 151R is in
contact with the spacer pressing surface 152Rr of the movable member 152R by
the tension spring 153 as described above. Therefore, when the second force
receiving portion 152Rn is pressed in the arrow W42 direction, the movable
member 152R rotates in the direction of the arrow BB about the movable member
swing axis HC, and the spacer pressing surface 152Rr presses the restricted
portion 151Rd, by which the spacer 151R is rotated in the direction of arrow B2.
When the spacer 151R rotates in the direction of arrow B2, the contact surface
151Rc separates from the contacted surface 116c, and the developing unit 109
can rotate in the direction of arrow V2 about the swing axis K from the separated
position. That is, the developing unit 109 rotates in the V2 direction from the
separated position, and the developing roller 106 of the developing unit 109 is brought into contact with the photosensitive drum 104. More specifically, the developing roller 106 includes a metal shaft (core metal), a rubber layer covering the metal shaft (core metal), and a roller mounted to the metal shaft at an axial end more than the rubber layer, and the surface of the rubber layer and the roller is contacted with the photosensitive drum 104. Since the rubber layer is deformed, the distance between the rotating axis M2 of the developing roller 106 and the rotating axis M1 of the photosensitive drum 104 can be accurately maintained by determining the distance between the rotating axis M2 of the developing roller 109 and the rotating axis M1 of the photosensitive drum 104.
[0443] Here, the position of the developing unit 109 in which the developing
roller 106 and the photosensitive drum 104 are in contact with each other is
referred to as a contact position (development position) (state of part (b) of Figure
1. The contact position (development position) in which the developing roller
106 is in contact with the photosensitive drum 104 is not only the position where
the surface of the developing roller 106 is in contact with the surface of the
photosensitive drum 104, but the position where the toner carried on the surface
of the photosensitive drum 104 can contact the surface of the photosensitive drum
104 when the developing roller 106 rotates is also included. That is, it can be
said that the contact position is a developing position where the toner carried on
the surface of the developing roller 106 can be transferred (deposited) to the
surface of the photosensitive drum 104 when the developing roller 106 rotates.
The position where the contact surface 151Rc of the spacer 151R is spaced from
the contacted surface 116c is referred to as a separation release position
(permitted position, second position). When the developing unit 109 is in
contact position, the restriction surface 151Rk of the spacer 151R is in contact
with the spacer restriction surface (spacer portion restriction portion) 116d of the
drive-side cartridge cover 116. By this, the spacer 151R is constrained from moving to the separation holding position and is maintained at the separation release position.
[0444] Further, the drive-side bearing 126 has a first pressed surface (at
separation pressed portion) 126c which is a surface perpendicular to the swing
axis K. The drive-side bearing is fixed to the developing unit 109. Therefore,
when the developing unit 109 presses the first force receiving portion 152Rk of
the movable member 152R in the direction of an arrow 41 when the developing
unit 109 is in the contact position, the developing frame pressing surface 152Rq
comes into contact with the first pressed surface 126c. By this, the developing
unit 109 rotates about the swing axis K in the direction of the arrow VI to move
to the separated position (retracted position) (state of part (a) of Figure 1. Here,
when the developing unit 109 moves from the contact position to the separated
position, the direction in which the first force receiving surface 126c moves is
shown by arrow W41 in part (a) of Figure 1 and part (b) of Figure 1. Further,
the direction opposite to the arrow W41 is indicated by arrow W42, and the
direction of the arrow W41 and the direction of the arrow W42 are substantially
horizontal directions (X1, X2 directions). The second force receiving surface
152Rp of the movable member 152R assembled to the developing unit 109 as
described above is placed on the upstream side of the first force receiving surface
126c of the drive-side bearing 126 in the arrow W41 direction. Further, the first
force receiving surface 126c and the pressed surface 151Re of the spacer 151R
are arranged at positions where at least a portion of them overlap in the Wi and
W2 directions. The detailed operation of the separation/contact mechanism
150R in the image forming apparatus main assembly 170 will be described below.
[Mounting of process cartridge 100 to image forming apparatus main assembly
170 (drive-side)]
[0445] Next, referring to Figures 12, 23, and 24, engaging operation of 195 will be described between the separation/contact mechanism 150R of the process cartridge 100 and the development separation control unit 195 of the image forming apparatus main assembly 170 at the time when the process cartridge 100 is mounted on the image forming apparatus main assembly 170. For better illustration, these Figures are cross-sectional views in which a portion of the development cover member 128 and a portion of the drive-side cartridge cover member 116 are partially omitted along the partial cross-sectional lines CS1 and
CS2, respectively.
[0446] Figure 23 is a view as seen from the drive-side of the process cartridge 100 when the process cartridge 100 is mounted on the cartridge tray 171 (not
shown) of the image forming apparatus M, and the cartridge tray 171 is inserted
into the first mounting position. In this Figure, portions other than the process
cartridge 100, the cartridge pressing unit 191 and the separation control member
196R are omitted.
[0447] As described above, the image forming apparatus main assembly 170 of this embodiment has separation control members 196R corresponding to
respective process cartridge 100 as described above. The separation control
member 196R is disposed on the lower surface side of the image forming
apparatus main assembly 170 with respect to the spacer 151R when the process
cartridge 100 is placed at a first inner position and a second inner position. The
separation control member 196R includes a first force application surface (force
applying portion, contact force applying portion) 196Ra and a second force
application surface (retracting force applying portion, separating force applying
portion) 196Rb which project toward the process cartridge 100 and face each
other through the space 196Rd. The first force application surface 196Ra and
the second force application surface 196Rb are connected with each other by a
connecting portion 196Rc on the lower surface side of the image forming apparatus main assembly 170. Further, the separation control member 196R is rotatably supported by the control sheet metal 197 with the rotation center 196Re as the center of rotation. The separating member 196R is normally urged in the
El direction by an urging member 196R. Further, by the control sheet metal
197 being structured to be movable in the W41 and W42 directions by a control
mechanism (not shown), the separation control member 196R is structured to be
movable in the W41 and W42 directions.
[0448] As described above, the cartridge pressing unit 191 lowers in the
direction of arrow ZA in interrelation with the transition of the front door 11 of
the image forming apparatus main assembly 170 from the open state to the closed
state, and a first force applying portion 191a comes into contact with the pressed
surface 152Rf of the movable member 152R. Thereafter, when the cartridge
pressing unit 191 is lowered to a predetermined position which is the second
mounting position, the projecting portion 152Rh of the movable member 152R
moves in the ZA direction (operating direction, predetermined direction) and
projects downward in the Z2 direction of the process cartridge 100 (state of
Figure 24). The ZA direction is a direction intersecting (orthogonally in this
embodiment) the rotation axis M2 of the developing roller 106, the rotation axis
M1 of the photosensitive drum 108 and the swing axis HC. Thispositionis
referred to as projecting positions of the movable member 152R and the
projecting portion 152Rh. The projecting position can also be referred to as a
force receiving position or an operating position. The projecting portion 152Rh
projects more from the developing frame when it is in the projecting position than
when it is in the stand-by position. When this operation is completed, as shown
in Figure 24, a gap T4 is formed between the first force application surface
196Ra of the separation control member 196R and the second force receiving
surface 152Rp of the movable member 152R, and a gap T3 is formed between the second force application surface 196Rb and the first force receiving surface 152
Rm. Then, it is located at the second mounting position where the separation
control member 196R does not act on the movable member 152R. It can be said
that this position of the separation control member 196R is a home position. At
this time, the second force receiving surface 152Rp of the movable member 152R
and the first force application surface 196Ra of the separation control member
196R are arranged so as to partially overlap with each other in the W41 and W42
directions. Similarly, the first force receiving surface 152Rm of the movable
member 152R and the second force application surface 196Rb of the separation
control member 196R are arranged so as to partially overlap in the W41 and W42
directions.
[Contact operation of developing unit (drive-side)]
[0449] Next, the contacting operation between the photosensitive drum 104
and the developing roller 106 by the separation/contact mechanism 150R will be
described in detail referring to Figures 24 to 26. For better illustration, in these
Figures, a portion of the development cover member 128, a portion of the drive
side cartridge cover member 116, and a portion of the drive-side bearing 126 are
partly omitted along partial cross-sectional lines CS1, CS2, and CS3, respectively.
[0450] In the structure of this embodiment, the development coupling 32
receives a driving force from the image forming apparatus main assembly 170 in
the direction of arrow V2 in Figure 24, so that the developing roller 106 rotates.
That is, the developing unit 109 including the development coupling 32 receives
torque (driving torque) in the arrow V2 direction about the swing axis K from the
image forming apparatus main assembly 170. The case where the developing
unit 109 shown in Figure 24 is in the separated position and the spacer 151R is in
the separation holding position will be described. In such a case, even if the
developing unit receives this driving torque and the urging force of the development pressure spring which will be described hereinafter, the attitude of the developing unit 109 is maintained at the separated position because the contact surface 151Rc of the spacer 15IR contacts the contacted surface 116c of the drive-side cartridge cover member 116.
[0451] The separation control member 196R of this embodiment is structured to be movable in the arrow W42 direction of in Figure 24 from the home position.
When the separation control member 196R moves in the W42 direction, the
second force application surface 196Ra of the separation control member 196R
and the second force receiving surface 152Rp of the second force receiving
portion 152Rn of the movable member 152R come into contact with each other, so that the movable member 152R rotates in the BB direction with the movable
member swing axis HC as the center of rotation. The contact between the first
force application surface 196Ra and the second force receiving surface 152Rp is
not necessarily surface contact, and may be line contact or point contact. In this
manner, the first force application surface 196Ra applies a contact force to the second force receiving surface 152Rp. The moving direction of the projecting
portion 152Rh when the movable member 152R is rotated in the BB direction is
referred to as a first direction. Further, as the movable member 152R rotates in
the BB direction, the spacer 151R is rotated in the B2 direction while the spacer
pressing surface 152Rr of the movable member 152R is in contact with the
pressed surface 151Re of the spacer 151R. The spacer 151R is rotated by the
movable member 152R to the separation release position (second position) where the contact surface 151Rc and the contacted surface 116c are separated from each
other. Here, the position of the separation control member 196R for moving the
spacer 151R to the separation release position (second position) shown in Figure
25 is referred to as a first position.
[0452] When the spacer 151R is moved to the separation release position
(second position) by the separation control member 196R in this manner, the
developing unit 109 rotates in the V2 direction by the drive torque received from
the image forming apparatus main assembly 170 and the development pressure
spring (biased portion) 134 which will be described hereinafter. Then, the
developing unit 109 moves to the contact position where the developing roller
106 and the photosensitive drum 104 contact each other (state in Figure 25). At
this time, the spacer 151R urged in the direction of arrow B1 by the tension
spring 153 is maintained at the separation release position (second position) by
the restricted surface 151Rk contacting to the spacer restriction surface 116d of
the drive-side cartridge cover member 116. After that, the separation control
member 196R moves in the direction of W41 and returns to the home position.
At this time, the movable member 152R is rotated in the BA direction by the
tension spring 153, and the state is shifted such that the developing frame
pressing surface 152Rq of the movable member 152R and the first pressing
surface 126c of the drive-side bearing 126 are in contact with each other is
reached (state shown in Figure 26). At this time, it can be said that the movable
member 152R and the projecting portion 152Rh are in the operating position.
[0453] By this, the above-mentioned gaps T3 and T4 are formed again, and
are located at positions where the separation control member 196R does not act
on the movable member 152R. The change from the state of Figure 25 to the
state of Figure 26 is performed without delay.
[0454] As described above, in the structure of this embodiment, by the
movement of the separation control member 196R from the home position to the
first position, the force is applied to the movable member 152R, so as to rotate
the movable member 152R and move the spacer 151R to the separation release
position (second position) from the separation holding position (first position).
This makes it possible for the developing unit to move from the separated position to the contacting position where the developing roller 9 and the photosensitive drum 104 are in contact with each other. That is, the contact force applied from the separation control member 196R is transmitted to the spacer 151R by way of the movable member 152R to move the spacer 151R from the separation holding position (first position) to the separation release position
(second position), by which the developing unit 109 is moved from the spaced
position (retracted position) to the contact position (developed position).
[0455] When the developing unit 109 is in the contact position (development
position), it is urged in the V2 direction by the driving torque received from the
image forming apparatus main assembly 170 and the development pressure
spring 134, and the position of the developing unit relative to the drum unit 108 is
determined by the roller 106 contacting to the photosensitive drum 104.
Therefore, the photosensitive drum can be said to be a positioning portion
(second positioning portion) which determines the position of the developing unit
109 at the developing position relative to the drum unit 108. Further, at this
time, it can be said that the developing unit 109 is stably held by the drum unit
108. At this time, the spacer 15IR in the separation release position is not
directly contributable to the positioning of the developing unit 109. However,
the spacer 151R does not prevent (permits) the developing roller 106 from
contacting the photosensitive drum 104 and determining the position of the
developing unit 109 relative to the drum unit 108 by moving from the separation
holding position to the separation release position. That is, it can be said that
the spacer 151R at the separation release position (second position) creates a
situation in which the drum unit 108 can stably hold the developing unit 109 at
the contact position (development position).
[0456] When the spacer 151R is in the separation release position (second
position), the position of the developing unit 109 with respect to the drum unit
108 may be determined by way of the spacer 151R as long as the developing
roller 106 is in contact with the photosensitive drum 104. In such a case, a
surface different from the contact portion 151Rc of the spacer 151R may be
brought into contact with the drive-side cartridge cover member 116, and the
development cover member 128 may be positioned by the drive-side cartridge
cover member 116 by way of the spacer 151R (sandwiched), for example.
[0457] The position of the separation control member 196R in Figure 26 is the
same as that in Figure 24.
[0458] Further, when the front door 11 of the image forming apparatus main
assembly 170 shifts from the closed state to the open state in this state, the first
force applying portion 191a rises in the direction opposite to the arrow ZA
direction. Along with this operation, the movable member 152R moves in the
direction opposite to the arrow ZA direction by the action of the urging member
153. However, the spacer 151R still maintains the separation release position,
and the developing unit 109 also maintains the developing position.
[Separation operation of developing unit (drive-side)]
[0459] Next, referring to Figures 26 and 27, the description will be made as to
the operation of moving the developing unit 109 from the contact position to the
spaced position by the separation/contact mechanism 150R. For better
illustration, these Figures are cross-sectional views in which a portion of the
development cover member 128, a portion of the drive-side cartridge cover
member 116, and a portion of the drive-side bearing 126 are partially omitted in
the partial cross-sectional line CS, respectively.
[0460] As described above, in the state shown in Figure 26, it can be said that
the movable member 152R and the projecting portion 152Rh are in the operating
position. The separation control member 196R in this embodiment is structured
to be movable from the home position in the W41 direction in Figure 26. When the separation control member 196R moves in the W41 direction, the second force application surface 196Rb and the first force receiving surface 152Rm of the first force receiving portion 152Rk of the movable member 152R come into contact with each other, and the movable member 152R rotates in the direction of arrow BA about the swing axis HC for the movable member. The contact between the second force application surface 196Rb and the first force receiving surface 152Rm is not necessarily surface contact, but may be line contact or point contact. In this manner, the second force application surface 196Rb applies a separating force (retracting force) to the first force receiving surface 152Rm.
The moving direction of the projecting portion 152Rh at the time when the
movable member 152R is rotated in the BA direction is referred to as a second
direction. Then, by the developing frame pressing surface 152Rq of the
movable member 152R being brought into contact with the first pressed surface
126c of the drive-side bearing 126, the developing unit 109 rotates from the
contact position in the direction of the arrow VI about the swing axis K (State of
Figure 27). Here, the pressed surface 152Rf of the movable member 152R
forms an arc shape, and the center of the arc is disposed so as to be aligned with
the swing axis K. By doing so, when the developing unit 109 moves from the
contact position to the spaced position, the force received by the pressed surface
152Rf of the movable member 152R from the pressing unit 191 is directed in the
direction of the swing axis K. Therefore, the rotation of the developing unit 109
in the arrow V Idirection is not hindered. In the spacer 151R, the restricted
surface 15iRk of the spacer 15iR and the spacer restriction surface 116d of the
drive-side cartridge cover member 116 are separated, and the spacer 15iR rotates
in the direction of arrow B1 (direction from the separation release position to the
separation holding position) by the urging force of the tension spring 153. By
this, the spacer 151R rotates until the pressed surface 151Re contacts spacer pressing surface 152Rr of the movable member 152R, and by this contacting, it shifts to the separation holding position (first position). When the developing unit 109 is moved from the contact position to the separation position by the separation control member 196R and the spacer 151R is at the separation holding position (first position), A gap T5 is formed between the contact surface 151Re and the contacted surface 116Rc as shown in Figure 27. Here, the position shown in Figure 27 in which the developing unit 109 is rotated from the contact position toward the separation position, and the spacer 151R can move to the separation holding position is referred to as a second position of the separation control member 196R.
[0461] Thereafter, the separation control member 196R moves in the arrow
W42 direction and returns from the second position to the home position. Then,
while the spacer 151R is maintained in the separation holding position, the
developing unit 109 is rotated in the arrow V2 direction by the driving torque
received from the image forming apparatus main assembly 170 and the
development pressure spring 134 described hereinafter, and the contact surface
151Rc contacts the contacted surface 116c. That is, the developing unit 109 is
in a state where the separated position is maintained by the spacer 151R, and the
developing roller 106 and the photosensitive drum 104 are spaced by the gap P1
(states in Figure 24 and part (a) of Figure 1. That is, the developing unit 109 is
constrained by the spacer 151R from moving to the contact position against the
driving torque received from the image forming apparatus main assembly 170
and the urging force in the arrow V2 direction due to the urging of the
development pressure spring 134, and the developing unit 109 is maintained in a
separated position. At this time, it can be said that the developing unit 109 is
stably held in a separated position (retracted position) by the drum unit 108. By
this, the above-mentioned gaps T3 and T4 are formed again, and are located at positions where the separation control member 196R does not act on the movable member 152R (state shown in Figure 24). The transition from the state of
Figure 27 to the state of Figure 24 is executed without a delay.
[0462] As described above, in this embodiment, the spacer 15IR moves from
the separation release position to the separation holding position by moving the
separation control member 196R from the home position to the second position.
Then, by the separation control member 196R returning from the second position
to the home position, the developing unit 109 becomes in a state of maintaining
the separation position by the spacer 151R. In this manner, the separation force
applied from the separation control member 196R is transmitted to the first
pressed surface 126c of the drive-side bearing (portion of the development frame)
126 by way of the movable member 152R, so that the developing unit is moved
from the contact position to the separation position (retracted position), and the
spacer 151R is moved from the separation release position to the separation
holding position.
[0463] In the state that the developing unit 109 is in the separated position
(retracted position), the position of the developing unit 109 with respect to the
drum unit 108 is determined by being urged in the V2 direction by the driving
torque received from the image forming apparatus main assembly 170 and the
development pressure spring 134 in the state that the supported portion 151Ra is
in contact with the first supported portion 128c, and the contact portion 151Re is
in contact with the contacted surface 116c, as described above. Therefore, the
contacted surface 116c can be said to be a positioning portion (first positioning
portion) for positioning the developing unit 109 at the separated position
(retracted position). At this time, it can be said that the developing unit 109 is
stably held by the drum unit 108. Further, it can be said that the spacer 151R at
the separation holding position (first position) establishes a situation in which the drum unit 108 can stably hold the developing unit at the separation position
(retracted position).
[0464] Further, when the front door 11 of the image forming apparatus main
assembly 170 shifts from the closed state to the open state in this state, the first
force applying portion 191a rises in the direction opposite to the arrow ZA
direction. Along with this, the movable member 152R moves in the direction
opposite to the arrow ZA direction by the action of the urging member 153.
However, the spacer 151R still maintains the separation holding position, and the
developing unit 109 also maintains the separation position.
[Detailed description of spacer L]
[0465] Here, the spacer 15iL will be described in detail referring to Figure 28.
Part (a) of Figure 28 is a front view of the spacer 15iL of as viewed in the
longitudinal direction of the drive-side of the process cartridge 100, and part (b)
of Figure 28 and part (c) of Figure 28 are perspective views of the spacer 151L
perse. The spacer 151L is provided with the annular supported portion 151La,
and is provided with a separation holding portion (holding portion) 151Lb
projecting from the supported portion 151La in the radial direction of the
supported portion 151La. The free end of the separation holding portion 151Lb
has an arc-shaped contact surface (contact portion) 151Lc centered on the swing
shaft Hof the spacer 151L. The swing shaftH of the spacer 151L is the same as
the swing shaft H of the spacer 151R.
[0466] The separation holding portion (holding portion) 151Lb is a portion
which connects the supported portion 151La and the contact surface 151Lc with
each other, and is sandwiched between the drum unit 108 and the developing unit
109 and has sufficient rigidity to maintain the separating position.
[0467] Further, the spacer 151L has a restricted surface (restricted portion)
15ILk adjacent to the contact surface 151Lc. Further, the spacer 15IL has a restricted portion 151Ld projecting in the Z2 direction from the supported portion
151La, and has an arc-shaped pressed portion 151Le (at-contact pressed portion)
projecting from the restricted portion 151Ld in the direction of the swing axis H
of the supported portion 151L a.
[0468] Further, the spacer 15iL has a main body portion 151Lf connected to
the supported portion 151La, and the main body portion 151Lf is provided with a
spring-hooked portion 151Lg projecting in the swing axis H direction of the
supported portion 151La. Further, the main body portion 151Lf has a rotation
prevention portion 151m projecting in the Z2 direction, and a rotation prevention
surface 151Ln is provided in a direction opposing the pressed portion 151Le.
[Detailed description of movable member L]
[0469] Here, referring to Figure 29, the movable member 152L will be
described in detail. Part (a) of Figure 29 is a front view of the movable member
152L per se as viewed from the longitudinal direction of the process cartridge
100, and part (b) of Figure 29 and part (c) of Figure 29 are perspective views of
the movable member 152L.
[0470] The movable member 152L is provided with the oblong supported
portion 152La. Here, the longitudinal direction of the oblong shape of the
oblong supported portion 152La is referred to as an arrow LH, the upward
direction is referred to as an arrow LH1, and the downward direction is referred
to as an arrow LH2. Further, the direction in which the oblong supported
portion 152La is formed is defined as HD. The movable member 152L is
provided with the projecting portion (force receiving portion) 152Lh formed on
the downstream side, in the arrow LH2 direction, of the oblong supported portion
152La. The oblong supported portion 152La and the projecting portion 152Lh
are connected with each other by the main body portion 152Lb. On the other
hand, the movable member 152L is provided with a pressed portion 152Le projecting in the direction substantially perpendicular to the direction of arrow
LH1, and an arc-shaped pressed surface (moving force receiving portion,
operating force receiving portion) 152Lf at a position downstream in the arrow
LH1 direction, a push-restricting surface 152Lg on the upstream side. Further,
the movable member 152L has a first restricted surface (first restricted portion)
152Lv which is a portion of the oblong supported portion 152La and which is
located on the downstream side in the arrow LH2 direction.
[0471] The projecting portion 152Lh is a first force receiving portion
(retracting force receiving portion, separating force receiving portion) 152Lk and
a second force receiving portion (contact force receiving portion) 152Ln which
are provided opposed to each other in a direction substantially perpendicular to
the arrow LH2 direction, at the end in the arrow LH2 direction. The first force
receiving portion 152Lk and the second force receiving portion 152Ln are
provided with a first force receiving surface (retracting force receiving surface, a
separating force receiving surface) 152Lm and a second force receiving surface
(contact force receiving surface) 152L Page which extend in the HD direction and
which have arc shapes, respectively. Further, the projecting portion 152Lh is
provided with a spring-hooked portion 152Ls projecting in the HB direction and a
locking portion 152Lt, and the locking portion 152Lt is provided with a locking
surface 152Lu facing in the same direction as the second force receiving surface
152Lp.
[0472] Further, the movable member 152L is a part of the main body portion
152Lb, is disposed on the upstream side in the arrow LH2 direction from the
second force receiving portion 152Ln, and has a developing frame pressing
surface (developing frame pressing portion, at-separation pressing portion) 152Lq
facing in the same direction as the second force receiving surface 152Lp.
Further, the movable member 152L is a part of the main body portion 152Lb and is disposed on the upstream side in the arrow LH2 direction from the first force receiving portion 152Lk, and has a spacer pressing surface (spacer portion pressing portion, at-contact pressing portion) 152Lr facing in the same direction as the first force receiving surface 152Lm.
[0473] When the process cartridge 100 is mounted on the image forming
apparatus main assembly 170, the LH1 direction is substantially the same as the
Z1 direction, and the LH2 direction is substantially the same as the Z2 direction.
Further, the HB direction is substantially the same as the longitudinal direction of
the process cartridge 100.
[Assembly of separation/contact mechanism 150L]
[0474] Next, referring to Figures 16 and 29 to 35 the assembling of the
separation mechanism will be described. Figure 30 is a perspective view of the
process cartridge 100 after the spacer 15IL is assembled thereto as viewed from
the drive-side. As described above, as shown in Figure 16, the developing unit
109 is supported so as to rotatable relative to the photosensitive drum 104 about
the swing axis K by fitting the outer diameter portion of the cylindrical portion
127a into the developing unit supporting hole 117a. Further, the non-drive-side
bearing 127 is provided with a first cylindrical support portion 127b and a second
cylindrical support portion 127e projecting in the direction of the swing axis K.
[0475] The outer diameter of the first supporting portion 127b fits with the
inner diameter of the supported portion 151La of the spacer 151L, and the spacer
151L isrotatably supported. Here, the swing axis of the spacer 151L assembled
to the non-drive-side bearing 127 is the swing axis H. The non-drive-side
bearing 127 is provided with a first retaining portion 127c projecting in the
direction of the swing axis H. As shown in Figure 16, the movement of the
spacer 151L assembled to the non-drive-side bearing 127 in the swing axis H
direction is restricted by the contact of the first retaining portion 127c with the spacer 151L.
[0476] Further, the outer diameter of the second supporting portion 127e fits
with the inner wall of the oblong supported portion 152La of the movable
member 152L, and supports the movable member 152L so as to be rotatable and
movable in the oblong direction. Here, the swing axis of the movable member
152L assembled to the non-drive-side bearing 127 is referred to as the movable
member swing axis HC. As shown in Figure 16, the movement of the movable
member 152L assembled to the non-drive-side bearing 127 in the movable
member swing axis HE direction is restricted by the contact of the second
retaining portion 127f with the spacer 151L.
[0477] Figure 31 is a view of the process cartridge 100 after assembling the
spacer 151L as viewed in the developing unit swing axis H direction. Itisa
cross-sectional view in which a portion of the non-drive-side cartridge cover
member 117 is partially omitted by the partial cross-sectional line CS so that the
fitting portion between the oblong supported portion 151La of the movable
member 152L and the cylindrical portion 127e of the non-drive-side bearing 127
can be seen. Here, the separation/contact mechanism 150L is provided with a
tension spring 153 as an urging member (holding portion urging member) a
spacer portion urging portion (holding portion urging portion) which urges the
spacer 151L to rotate in the direction of the arrow B1 about the swing axis H, and
provided with a force receiving portion urging portion (projecting portion urging
portion) urging the movable member 152L in the B3 direction indicated by the
arrow. The tension spring 153 is a coil spring and an elastic member. The
arrow B3 direction is a direction substantially parallel to the longitudinal
direction LH2 (Figure 29) of the oblong supported portion 152La of the movable
member 152L. The tension spring 153 is engaged and connected to the spring
hooked portion 151 Lg provided on the spacer 151 L and the spring-hooked portion 152Ls provided on the movable member 152 L, and is assembled between them. The tension spring 153 applies a force to the spring-hooked portion 151Lg of the spacer 15iL in the direction of arrow F2 in Figure 31 to impart an urging force to rotate the spacer 151L in the direction of arrow B1.
Further, the tension spring applies a force to the spring-hooked portion 152Ls of
the movable member 152L in the direction of the arrow Fl to move the movable
member 152L in the direction of the arrow B3 (direction toward the
accommodating position (reference position, stand-by position).
[0478] A line GS connects the spring-hooked portion 151Lg of the spacer 15iL and the spring-hooked portion 152Ls of the force holding member 152L, and a line HS connects the spring-hooked portion 152Ls of the movable member
152L and the movable member swinging axis HE. Then, an angle 03 formed by
the line GS and the line HS is set so as to satisfy the following equation (3) with
the counterclockwise direction being positive about the spring-hooked portion
152Ls of the movable member 152L. By this, the movable member 152L is urged to rotate in the BA direction in the drawing with the movable member
swinging axis HE as the center of rotation. 0° 03 90° .... (3)
[0479] As shown in Figure 29, the spacer 15L and the movable member 152L are mounted to the spacer on the side (longitudinal outside) of the non-drive
side bearing 127 on which the non-driving cartridge cover member 117 is
arranged in the direction of the swing axis K. However, the positions to be
arranged are not limited to this example, and they may be arranged on the
developing container 125 side (inside in the longitudinal direction) of the non
drive-side bearing 127, respectively, and the spacer 151L and the movable
member 152L may be arranged with the non-drive-side bearing interposed therebetween. Further, the order of the arrangement of the spacer 151L and the movable member 152L may be exchanged.
[0480] The non-drive-side bearing 127 is fixed to the developing container
125 to form the developing unit 109. As shown in Figure 16, the fixing method
in this embodiment is fixed by a fixing screw 145 and an adhesive (not shown),
but the fixing method is not limited to this, and welding such as welding by
heating or pouring and hardening of resin may be used.
[0481] Here, part (a) of Figure 32 and part (b) of Figure 32 are enlarged cross
sectional views of the movable member rocking axis HE and the distance holding
portion 151L of the movable member 152L in Figure 31 for better illustration.
Further, part (a) of Figures 32 and part (b) of Figure 32 are cross-sectional views
in which the non-drive-side cartridge cover member 117, the tension spring 153,
and the spacer 151L are partially omitted by the partial cross-sectional line CS.
In the movable member 152L, the first restricted surface 152Lv of the movable
member 152L is brought into contact with the second supporting portion 127e of
the non-drive-side bearing 127 by the urging force of the tension spring 153 in
the arrow F1 direction. Further, as shown in part (b) of Figure 32, the
developing frame pressing surface 152Lq of the movable member 152L is
brought into contact with the pressed surface 127h of the non-drive-side bearing
127 and is thereby positioned. This position is referred to as an accommodated
position of the movable member 152L. The accommodated position can also be
referred to as a reference position or a stand-by position. Further, the spacer
151L is rotated in the direction of the arrow B4 about the swing axis H by the
urging force of the tension spring 153 in the arrow F2 direction, and the contact
surface 151Lp of the spacer 15IL is positioned by contacting to the spacer
pressing surface 152Lr of the movable member 152L. This position is referred
to as a separation holding position (restriction position) of the spacer 151L.
When the movable member 152L moves to the projecting position which will be described hereinafter, the pressed portion 151Le of the spacer 151L contacts the spacer pressing surface 152Lr of the movable member 152L, so that the movable member 152L can be positioned at the separation holding position.
[0482] Further, Figure 33 is an illustration in which the periphery of the
separation holding portion 151L in Figure 31 is enlarged, and the tension spring
153 is omitted, for better illustration. Here, a case is considered in which the
process cartridge 100 including the separation/contact mechanism 150L drops in
the direction of an arrow JA in Figure 33 when the process cartridge 100 is
transported. At this time, the spacer 151L receives a force of rotating in the
direction of arrow B2 due to its own weight about the separation holding swing
axisH. When the spacer 151L starts to rotate in the arrow B2 direction for this
reason, the rotation prevention surface 151Ln of the spacer 151L comes into
contact with the locking surface 152Lu of the movable member 152L, and the
spacer 151L receives a force in the arrow F4 direction so as to suppress the
rotation in the arrow B2 direction. By this, it is possible to constrain the spacer
151L from rotating in the arrow B2 direction during transportation, and it is
possible to prevent impairment of the spaced state between the photosensitive
drum 104 and the developing unit 109.
[0483] In this embodiment, the tension spring 153 is mentioned as an urging
means for urging the spacer 15IL to the separation holding position and the
movable member 152L to the accommodated position, but the urging means is
not limited to this example. For example, a torsion coil spring, a leaf spring, or
the like may be used as an urging means to urge the movable member 152L to the
accommodated position and the spacer 151L to the separation holding position.
Further, the material of the urging means may be metal, a mold, or the like, which
has elasticity and can urge the spacer 15IL and the movable member 152L.
[0484] As described above, the developing unit 109 provided with the separation/contact mechanism 150L is integrally coupled with the drum unit 108 by the non-drive-side cartridge cover member 117 as described above (state of
Figure30). As shown in Figure 16, the non-drive-side cartridge cover 117 of
this embodiment has the contact surface (contact portion) 117c. The contacted
surface 117c is substantially parallel to the swing axis K. Further, as shown in
Figures 16 and 30, the contacted surface 117c opposes the surface 151Lc of the
spacer 151L located at the separation holding position when the non-drive-side
cartridge cover member 117 is assembled to the developing unit 109 and the
drum unit 108. Here, the process cartridge 100 has a development pressure
spring 134 as a developing unit urging member (a second unit urging member)
for urging the developing unit 109 from the spaced position toward the contact
position to bring the developing roller 106 into contact with the photosensitive
drum 104. The development pressure spring 134 is a coil spring assembled
between the spring-hooked portion 117e of the non-drive-side cartridge cover
member 117 and the spring-hooked portion 127k of the non-drive-side bearing
127, and is an elastic member. The urging force of the development pressing
spring 134 brings the contact surface 151Lc of the spacer 151L into contact with
the contacted surface 117c of the non-drive-side cartridge cover member 117.
Then, when the contacted surface 117cc and the contact surface 151Lc come into
contact with each other, the attitude of the developing unit 109 is determined with
a gap P1 between the developing roller 106 of the developing unit 109 and the
photosensitive drum 104. The state in which the developing roller 106 is spaced
from the photosensitive drum 104 by the gap P1 by the spacer 151L in this
manner is referred to as a separating position (retracted position) of the
developing unit 109 (part (a) of Figure 35.
[Separation state and contact state of process cartridge 100 (non-drive-side)]
[0485] Here, referring to Figure 34, the separated state and the contact state of the process cartridge 100 will be described in detail. Figure 34 is a side view of the process cartridge 100 as viewed from the non-drive-side with the process cartridge 100 mounted inside the image forming apparatus main assembly 170.
Part (a) of Figure 34 shows a state in which the developing unit is separated from
the photosensitive drum 104. Part (b) of Figure 34 shows a state in which the developing unit 109 is in contact with the photosensitive drum 104.
[0486] First, the description will be made as to the state in which the spacer 151L is located at the separation holding position (first position) and the
developing unit 109 is placed at the separation position (retracted position) will
be described. In this state, the supported portion 151La, which is one end of the
separation holding portion 151Lb, is in contact with the first supporting portion
127b of the non-drive-side bearing 127, and the contact portion 151Lc, which is
the other end, is in contact with the contacted surface 117c of the non-drive-side
cartridge cover member 117. Further, the first supporting portion 127b is
pressed toward the supported portion 151La by the action of the development pressure spring 134, and the contact portion 151Lc is pressed toward the
contacted surface 117c. Therefore, in this state, the non-drive-side cartridge
cover member 117 (which constitutes a portion of the drum unit 108) determines
the position of the non-drive-side bearing 127 (which constitutes a portion of the
developing unit 109) by way of the separation holding portion 151Lb of the
spacer 151L.
[0487] From this state, the pressed portion 152Le of the movable member 152L is pushed in the direction of arrow ZA. By this, the movable member
152L and the projecting portion 152Lh move linearly from the stand-by position
in the ZA direction (operating direction) to reach the projecting position. The
ZA direction is a direction which intersects (orthogonally in this embodiment) the
rotation axis M2 of the developing roller 106, the rotation axis M1 of the photosensitive drum 108, and the swing axis HE. Therefore, the projecting portion 152Lh at the time when it is in the projecting position is placed downstream in the ZA direction from the projecting portion 152Lh when it is in the stand-by position. Therefore, the projecting portion 152Lh when it is in the projecting position is placed more remote from the swing axis K than the projecting portion 152Lh when it is in the stand-by position. Further, the projecting portion 152Lh when it is at the projecting position projects in the ZA direction beyond the drum frame and the developing frame (placed downstream in the ZA direction). In this embodiment, the drum frame includes the first drum frame portion 115, the drive-side cartridge cover member 116, and the non drive-side cartridge cover member 117, and the developing frame includes the developing container 125, the drive-side bearing 126, and the non-drive-side bearing 127. The projecting position can also be referred to as a force receiving position or an operating position.
[0488] The movable member 152L is movable in the ZA direction and the
opposite direction while maintaining the state in which the spacer 151L is in the
separation holding position (first position). Therefore, also when the movable
member 152L and the projecting portion 152Lh are in the operating positions, the
spacer 151L is in the separation holding position (first position). Thepressed
portion 151Le of the spacer 151L is in contact with the spacer pressing surface
152Lr of the movable member 152L by the tension spring 153 as described above.
Therefore, when the second force receiving portion 152Ln (second force
receiving surface 152Lp) is pressed in the arrow W42 direction, the movable
member 152L rotates in the direction of the arrow BD about the movable member
swing axis HE, so that the spacer pressing surface 152Lr urges the pressed
portion 151Le, the spacer 151L is rotated in the direction of arrow B5. When
the spacer 151L rotates in the direction of arrow B5, the contact surface 151Lc separates from the contacted surface 117c, and the developing unit 109 becomes rotatable in the direction of arrow V2 about the swing axis K from the spaced position. That is, the developing unit 109 rotates in the V2 direction from the spaced position, and the developing roller 106 of the developing unit comes into contact with the photosensitive drum 104. Here, the position of the developing unit 109 in which the developing roller 106 and the photosensitive drum 104 contact with each other is referred to as a contact position (development position)
(state in part (b) of Figure 34. The position where the contact surface 151Lc of
the spacer 151L is separated from the contacted surface 117c is referred to as a
separation release position (permission position, second position). When the
developing unit 109 is placed at the contact position, the restriction surface
151Lk of the spacer 151L contacts the spacer restriction surface (spacer portion
restriction portion) 117d of the drive-side cartridge cover 116, so that the spacer
151L is maintained at the separation release position.
[0489] Further, the non-drive-side bearing 127 of this embodiment is provided with a pressed surface (pressed portion at the time of separation) 127h which is a
surface perpendicular to the swing axis K. The non-drive-side bearing 127 is
fixed to the developing unit 109. Therefore, when the first force receiving
portion 152Lk (first force receiving surface 152Lm) of the movable member
152L is urged in the direction of the arrow 41 while the developing unit 109 is in the contact position, the developing frame pressing surface 152Lq comes into
contact with the pressed surface 127h. By this, the developing unit 109 rotates
about the swing axis K in the direction of the arrow VI to move to the separated
position (state of part (a) of Figure 34. Here, when the developing unit 109
moves from the contact position to the separated position, the direction in which
the pressed surface 127h moves is indicated by arrow W41 in part (a) of Figure
34 and part (b) of Figure 34. Further, the direction opposite to the W41 direction is indicated by the arrow W42, and the arrow W41 direction and the arrow W42 direction are substantially horizontal directions (X1, X2 directions).
The second force receiving surface 152Lp of the movable member 152L
assembled to the developing unit 109 as described above is placed on the
upstream side of the pressed surface 127h of the non-drive-side bearing 127 in the direction of the arrow W41 direction. Further, the pressed surface 127h and
the pressed portion 151Le of the spacer 15IL are placed at positions where at
least parts of them overlap in the WI and W2 directions. The operation of the
separation/contact mechanism 150L in the image forming apparatus main
assembly 170 will be described hereinafter.
[Mounting of process cartridge 100 to image forming apparatus main assembly
170 (non-drive-side)]
[0490] Next, referring to Figures 35 and 36, the description will be made as to the engaging operation between the separation/contact mechanism 150L of the
process cartridge 100 and the development separation control unit 196L of the image forming apparatus main assembly 170 when the process cartridge 100 is
mounted in the image forming apparatus main assembly 170. These Figures are
cross-sectional views in which a part of the development cover member 128 and
a part of the non-drive-side cartridge cover member are omitted by the partial
cross-sectional line CS, respectively, for better illustration. Figure 35 is a view
as seen from the drive-side of the process cartridge 100 when the process
cartridge 100 is mounted on the cartridge tray 171 (not shown) of the image
forming apparatus M and the cartridge tray 171 is inserted to the first mounting
position. In Figure 35, portions other than the process cartridge 100, the
cartridge pressing unit 190, and the separation control member 196L are omitted.
[0491] As described above, the image forming apparatus main assembly 170 of this embodiment is provided with a separation control member 196L corresponding to each process cartridge 100 as described above. The separation control member 196L is disposed on the lower surface side of the image forming apparatus main assembly 170 with respect to the spacer 151L when the process cartridge 100 is placed at the first inner position and the second inner position.
The separation control member 196L has the first force application surface (force
applying portion) 196La and the second force application surface (retracting force
applying portion) 196Lb which project toward the process cartridge 100 and face
each other across the space 196Rd. The first force application surface 196Ra
and the second force application surface 196Rb are connected by a connecting
portion 196Rc on the lower surface side of the image forming apparatus main
assembly 170. Further, the separation control member 196R is supported by the
control sheet metal 197 so as to be rotatable about the rotation center 196Re.
The separating member 196R is normally urged in the E l direction by the urging
spring. Further, the control sheet metal 197 is structured to be movable in the
W41 and W42 directions by a control mechanism (not shown), so that the
separation control member 196R is movable in the W41 and W42 directions.
[0492] The cartridge pressing unit 190 lowers in the direction of arrow ZA in
interrelation with the transition of the front door 11 of the image forming
apparatus main assembly 170 from the open state to the closed state, as described
above, and the first force applying portion 190a is brought into contact with the
pressed surface 152Lf of the movable member 152L. Thereafter, when the
cartridge pressing unit 190 is lowered to a predetermined position which is the
second mounting position, the projecting portion 152Lh of the movable member
152L moves to a projecting position where it projects downward of the process
cartridge 100 in the Z2 direction (state in Figure 36). When this operation is
completed, the gap T4 is formed between the first force application surface
196La of the separation control member 196L and the second force receiving surface 152Lp of the movable member 152L, and the gap T3 is formed between the second force application surface 196Lb and the first force receiving surface
152Lm, as shown in Figure 36. Then, it is placed at the second mounting
position where the separation control member 196L does not act on the movable
member 152L. This position of the separation control member 196L is referred
to as a home position. At this time, the second force receiving surface 152Lp of
the movable member 152L and the first force application surface 196La of the
separation control member 196L are arranged so as to partially overlap in the W1
and W2 directions. Similarly, the first force receiving surface 152Lm of the
movable member 152L and the second force application surface 196Lb of the
separation control member 196L are arranged so as to partially overlap in the W1
and W2 directions.
[Contact operation of developing unit (non-drive-side)]
[0493] Next, referring to Figures 36 to 38, the description will be made as to
the operation in which the photosensitive drum 104 and the developing roller 106
are brought into contact with each other by the separation/contact mechanism
150L. For better illustration, a part of the development cover member 128, a
part of the non-drive-side cartridge cover member 117, and a part of the non
drive-side bearing 127 are omitted by the partial cross-sectional line CS,
respectively in the sectional view.
[0494] As described above, the development coupling 32 receives a driving
force from the image forming apparatus main assembly 170 in the direction of
arrow V2 in Figure 24, and the developing roller 106 rotates. That is, the
developing unit 109 including the development coupling 32 receives the driving
torque in the arrow V2 direction about the swing axis K from the image forming
apparatus main assembly 170. Further, the developing unit 109 also receives an
urging force in the arrow V2 direction due to the urging force of the development pressure spring 134 described above. As shown in Figure 36, a state in which the developing unit 109 is in the separated position and the spacer 151L is in the separation holding position (first position) will be described. In this state, even if the developing unit 109 receives this driving torque and the urging force of the development pressure spring 134, the contact surface 151Lc of the spacer 151L contacts the contacted surface 117c of the non-drive-side cartridge cover member
117. Therefore, the attitude of the developing unit 109 is maintained in the
separated position.
[0495] The separation control member 196L of this embodiment is structured
to be movable from the home position in the W41 direction in Figure 36. When
the separation control member 196L moves in the W41 direction, the first force
application surface 196La of the separation control member 196L and the second
force receiving surface 152Lp of the second force receiving portion 152Ln of the
movable member 152L come into contact with each other, and the movable
member 152L rotates in the BD direction about the swing axis HD. The contact
between the first force application surface 196La and the second force receiving
surface 152Lp is not necessarily surface contact, and may be line contact or point
contact. In this manner, the first force application surface 196La applies a
contact force to the second force receiving surface 152Lp by moving in the W41
direction. The moving direction of the projecting portion 152Lh when the
movable member 152L is rotated in the BD direction is referred to as the first
direction. Further, as the movable member 152L rotates, while the spacer
pressing surface 152Lr of the movable member 152L is in contact with the
pressed portion 15ILe of the spacer 15IL, the spacer 15IL is rotated in the B5
direction. Then, the spacer 151L is rotated by the movable member 152L to the
separation release position (second position) where the contact surface 151Lc and
the contacted surface 117c are spaced from each other. Here, the position of the separation control member 196L for moving the spacer 151L to the separation release position (second position) shown in Figure 37 is referred to as a first position.
[0496] When the spacer 15iL is moved to the separation release position by
the separation control member 196L in this manner, the developing unit 109
rotates in the V2 direction by the driving torque received from the image forming
apparatus main assembly 170 and the urging force of the development pressure
spring 134. By this, the developing unit 109 moves to the contact position
where the developing roller 106 and the photosensitive drum 104 contact each
other (state in Figure 37). At this time, the spacer 151L urged in the direction of
arrow B4 by the tension spring 153 is maintained at the separation release
position (second position) by the contact of the restricted surface 151Lk with the
spacer restriction surface 117d of the non-drive-side cartridge cover member 117.
Thereafter, the separation control member 196L moves in the direction of W42
and returns to the home position. At this time, the movable member 152L is
rotated in the BC direction by the tension spring 153, to establish the state in
which the developing frame pressing surface 152Lq of the movable member
152L and the pressed surface 127h of the non-drive-side bearing 127 are in
contact with each other (state of Figure 38). At this time, it canbe said that the
movable member 152L and the projecting portion 152Lh are in the operating
positions.
[0497] By this, the above-mentioned gaps T3 and T4 are formed again, and
the separation control member 196L is placed at the position where it does not act
on the movable member 152L. The transition from the state of Figure 37 to the
state of Figure 38 is performed without a delay. The position of the separation
control member 196L in Figure 38 is the same as that in Figure 36.
[0498] Further, in the above description, it is assumed that the second force receiving surface 152Lp is subjected to the contact force from the first force application surface 196La. In this regard, the contact force is a force applied from the first force application surface 196La moving in the W41 direction, and this is a force applied to the process cartridge 100 to move it in a direction
(contact direction, approaching direction, or V2 direction) in which the
developing roller 106 comes closer and contacts to the photosensitive drum 104.
Therefore, it is sufficient if the developing unit 109 moves from the retracted
position to the developing position triggered by receiving the contact force, and it
is not necessary that the process cartridge continues to receive the contact force
until the developing unit 109 reaches the developing position. As described
above, it is unnecessary that when the developing unit shifts from the retracted
position to the developing position by the contact force, the developing roller 106
and the photosensitive drum 104 are in contact with each other at the developing
position.
[0499] As described above, in the structure of this embodiment, the separation
control member 196L moves from the home position to the first position to apply
a contact force to the movable member 152L, rotate the movable member 152L,
and hold the spacer 151L in the separation holding position. Itcanbemoved
from the (first position) to the separation release position (second position). By
doing so, it is possible for the developing unit 109 to move from the separated
position to the contacting position where the developing roller 9 and the
photosensitive drum 104 come into contact with each other. That is, it can be
said that the contact force applied from the separation control member 196L is
transmitted to the spacer 151L by way of the movable member 152L, so that the
developing unit 109 moves from the separated position (retract position) to the
contact position (development position).
[0500] In the state that the developing unit 109 is in the contact position
(development position), the position of the developing unit 109 relative to the
drum unit 108 is determined by the developing unit 109 being urged in the V2
direction by the driving torque received from the image forming apparatus main
assembly 170 and the development pressure spring 134 by which the developing
roller 106 is in contact with the photosensitive drum 104. Therefore, the
photosensitive drum 104 can be said to be a positioning portion (second
positioning portion) for positioning the developing roller 6 of the developing unit
109 at the developing position. At this time, it can be said that the developing
unit 109 is stably held by the drum unit 108. At this time, the spacer 151L in the
separation release position is not directly contributable to the positioning of the
developing unit 109. However, it can be said that the spacer 151L creates the
situation in which the drum unit 108 can stably hold the developing unit 109 at
the contact position (development position) by moving from the separation
holding position to the separation release position.
[0501] Further, when the front door 11 of the image forming apparatus main
assembly 170 shifts from the closed state to the open state in this state, the first
force applying portion 190a rises in the direction opposite to the arrow ZA
direction. Along with this, the movable member 152R moves in the direction
opposite to the arrow ZA direction by the action of the urging member 153.
However, the spacer 151R still maintains the separation release position, and the
developing unit 109 also maintains the developing position.
[Separation operation of developing unit (non-drive-side)]
[0502] Referring to Figures 38 and 39, the operation of moving the developing
unit 109 from the contact position to the separation position will be described in
detail. Figure 39 is a cross-section in which a part of the development cover
member 128, a part of the non-drive-side cartridge cover member 117, and a part
of the non-drive-side bearing are partially omitted by the partial cross-section line
CS, respectively.
[0503] As described above, in the state shown in Figure 38, it can be said that
the movable member 152L and the projecting portion 152Lh are in the operating
position. The separation control member 196L in this embodiment is structured
to be movable from the home position in the direction of W42 in Figure 38.
When the separation control member 196L moves in the W42 direction, the
second force application surface 196Lb and the first force receiving surface
152Lm of the first force receiving portion 152Lk of the movable member 152L
are brought into contact with each other, and the movable member swings 152L
about the swing axis HD in the direction of arrow BC. The contact between the
second force application surface 196Lb and the first force receiving surface
152Lm is not necessarily surface contact, and may be line contact or point contact.
In this manner, the second force application surface 196Lb applies a separating
force (retracting force) to the first force receiving surface 152Lm. The moving
direction of the projecting portion 152Lh when the movable member 152L is
rotated in the BC direction is referred to as a second direction. Since the
developing frame pressing surface 152Lq of the movable member 152L is in
contact with the pressed surface 127h of the non-drive-side bearing 127, the
developing unit 109 rotates from the contact position in the arrow VI direction
about the swing axis K (state in Figure 39). At this time, the pressed surface
152Lf of the movable member 152L has an arc shape, and the center of the arc is
positioned so as to be the same as the swing axis K.
[0504] By this, when the developing unit 109 moves from the contact position
to the separating position, the force received by the pressed surface 152Lf of the
movable member 152L from the cartridge pressing unit 190 is directed in the
swing axis K direction. Therefore, the developing unit 109 can be operated so
as not to hinder the rotation in the arrow VI direction. In the spacer 151L, the restricted surface 151Lk of the spacer 151L and the spacer restriction surface
117d of the non-drive-side cartridge cover member 117 are separated from each
other, and the spacer 151L rotates in the arrow B4 direction (the direction from
the separation release position to the separation holding position) by the urging
force of the tension spring 153. By this, the spacer 151L rotates until the
pressed portion 151Le contacts to the spacer pressing surface 152LR of the
movable member 152L, and by the contacting, it shifts to the separation holding
position (first position).
[0505] When the developing unit 109 is moved from the contact position to
the separation position by the separation control member 196L, and the spacer
151L is located at the separation holding position, a gap T5 is formed between
the contact surface 151Lc and the contacted surface 117c as shown in Figure 39.
Here, the position where the developing unit 109 is rotated from the contact
position toward the separation position, and the spacer 151L can move to the
separation holding position is referred to as a second position of the separation
control member 196L.
[0506] Thereafter, the separation control member 196L moves in the W41
direction and returns from the second position to the home position. Then,
while the spacer 151L is maintained in the separation holding position, the
developing unit 109 rotates in the arrow V2 direction by the driving torque
received from the image forming apparatus main assembly and the urging force
of the development pressure spring 134, so that the contact surface 151Lc is
brought into contact with the contacted surface 117c. That is, the developing
unit 109 becomes in the state that the separated position is maintained by the
spacer 151L, and the developing roller 106 and the photosensitive drum 104 are
spaced from each other by the gap P1 (states in Figure 36 and part (a) of Figure
34. By this, the above-mentioned gaps T3 and T4 are formed again, and the state is reached in which the separation control member 196L does not act on the movable member 152L (state in Figure 36). The transition from the state of
Figure 39 to the state of Figure 36 is executed without a delay.
[0507] Further, in the above-described example, the first force receiving surface 152Lm receives a separation force (retracting force) from the second
force application surface 196Lb. In this regard, the separation force is a force
applied from the second force application surface 196Lb which moves in the
W42 direction, and is for moving the developing roller 106 in the direction away
from the photosensitive drum 104 (separation direction, retracting direction, or
VI direction). This is the force applied to the process cartridge 100. Therefore, it suffices if the developing unit 109 moves from the developing position to the
retracted position triggered by receiving the separating force as a trigger, and the
process cartridge 100 does not necessarily continues receiving the separating
force until the developing unit 109 reaches the retracting position.
[0508] As described above, in the structure of this embodiment, by the separation control member 196L moving from the home position to the second
position, the spacer 15IL moves from the separation release position to the
separation holding position. Then, the separation control member 196L
returning from the second position to the home position, the developing unit 109
becomes in a state of maintaining the separation position by the spacer 151L.
That is, the developing unit 109 is constrained by the spacer 151L from moving to the contact position against the driving torque received from the image forming
apparatus main assembly 170 and the urging force in the arrow V2 direction by
the urging of the development pressure spring 134, and therefore is maintained in
a separated position.
[0509] In this manner, the separation force applied from the separation control member 196L is transmitted to the pressed surface 127h of the non-drive-side bearing (a part of the developing frame) 127 by way of the movable member
152L, so that the developing unit 109 is moved from the contact position to the
separation position (retracted position), and the spacer 151R is moved from the
separation release position to the separation holding position.
[0510] With the developing unit 109 in the separated position (retracted
position), the position of the developing unit 109 with respect to the drum unit
108 is determined by the urging in the V2 direction by the driving torque received
from the image forming apparatus main assembly 170 and the development
pressure spring 134, the contacting of the supported portion 151La to the first
supporting portion 127b as described above, and the contacting of the contact
portion 151Lc to the contacted surface 117c. Therefore, the contacted surface
117c can be said to be a positioning portion (first positioning portion) for
positioning the developing unit 109 at the separated position (retracted position)
of the photosensitive drum 104. At this time, it can be said that the developing
unit 109 is stably held by the drum unit 108. Further, it can be said that the
spacer 151L at the separation holding position (first position) creates a state in
which the drum unit 108 can stably hold the developing unit at the separation
position (retracted position).
[0511] Further, when the front door 11 of the image forming apparatus main
assembly 170 shifts from the closed state to the open state in this state, the first
force applying portion 190a rises in the direction opposite to the arrow ZA
direction. Along with this, the movable member 152L moves in the direction
opposite to the arrow ZA direction by the action of the urging member 153.
However, the spacer 151L still maintains the separation holding position, and the
developing unit 109 also maintains the separation position.
[0512] So far, the operation of the separation mechanism located on the drive
side of the process cartridge 100 and the operation of the separation mechanism located on the non-drive-side have been described separately, but in this embodiment, they operate in interrelation with each other. That is, when the developing unit 109 is positioned at the separated position by the spacer 15IR, the developing unit 109 is positioned at the separated position by the spacer 151L at substantially the same time, and the same is true at the contact position. Specifically, the movements of the separation control member 196R and the separation control member 196L described in Figures 23 to 27 and Figures 35 to
39 are integrally moved by a connecting mechanism (not shown). By this, the
timing at which the spacer 151R located on the drive-side is placed at the
separation holding position and the timing at which the spacer 151L located on
the non-drive-side is placed at the separation holding position are substantially
simultaneous. Further, the timing at which the spacer 151R is placed at the
separation release position and the timing at which the spacer 151L is placed at
the separation release position are substantially the same. Note that these
timings may be different between the drive-side and the non-drive-side, but in order to shorten the time from the start of the print job by the user until the
printed matter is discharged, it is desirable that at least the timing at which it is
positioned at the separation release position is the same. In this embodiment, the swing axis H of the spacer 151R and the spacer 15L are coaxial, but the
present invention is not limited to this example, and it will suffice if the timings
of the spacers 151R and the spacers 15L may be substantially the same as those
at the separation release position as described above. Similarly, the swing axis
HC of the movable member 152R and the movable member swinging axis HE of
the movable member 152L are not coaxial, but the present invention is not
limited to such an example, and it is sufficient that the timings of being located at
the separation release positions are substantially the same as described above.
[0513] In order to perform the above-mentioned contact operation and separation operation, the width of the projecting portion 152Rh of the movable member 152R or the distance between the first force receiving surface 152Rm and the first force receiving surface 152Rp measured in the W41 direction or the
W42 direction is determined is preferably 10 mm or less, and more preferably 6
mm or less. With such a dimensional relationship, it is possible to perform an
appropriate contact operation and separation operation. The same applies to the
movable member 152L on the non-drive-side.
[0514] As described above, in this embodiment, the drive-side and the non
drive-side have similar separation/contact mechanisms 150R and 150L, and they
operate substantially at the same time. By this, even when the process cartridge
100 is twisted or deformed in the longitudinal direction, the amount of separation
between the photosensitive drum 104 and the developing roller 9 can be
controlled at both ends in the longitudinal direction. Therefore, it is possible to
suppress variations in the amount of separation along the longitudinal direction.
[0515] Further, according to this embodiment, by moving the separation
control member 196R (196L) between the home position, the first position, and
the second position in one direction (arrows W41 and W42 directions), it is
possible to control the contact state and the separation state between the
developing roller 106 and the photosensitive the drum 104. Therefore, the
developing roller 106 can be contacted with the photosensitive drum 104 only
when the image is formed, and the developing roller 4 can be maintained in the
spaced state from the photosensitive drum 104 when the image is not formed.
Therefore, even if the apparatus is unoperated left for a long time without
forming an image, the developing roller 106 and the photosensitive drum 104 are
prevented from being deformed, and a stable image formation can be formed.
[0516] Further, according to this embodiment, the movable member 152R
(152L) which acts on the spacer 151R (15IL) to rotationally move can be positioned at the accommodated position by the urging force of the tension spring
153 or the like. Therefore, when the process cartridge 100 is outside of the
image forming apparatus main assembly 170, the process cartridge 100 can be
downsized as a single unit without projecting from the outermost shape of the
process cartridge 100.
[0517] Similarly, the movable member 152R (152L) can be positioned at the
accommodated position by the urging force of the tension spring 153 or the like.
Therefore, when the process cartridge is mounted on the image forming apparatus
main assembly 170, the process cartridge 100 can be mounted by moving only in
one direction. Therefore, it is not necessary to move the process cartridge 100
(tray 171) both in the upward and downward directions. For this reason, the
image forming apparatus main assembly 170 does not require an extra space, and
the main assembly can be downsized.
[0518] In addition, according to this embodiment, when the separation control
member 196R (196L) is located at the home position, the separation control
member 196R (196L) is free of load thereto from the process cartridge 100.
Therefore, the rigidity required for the mechanism for operating the separation
control member 196R (196L) and the separation control member 196R (196L)
can be reduced, and the size thereof can be reduced. Further, the load on the
sliding portion of the mechanism for operating the separation control member
196R (196L) is also reduced, and therefore, wearing of the sliding portion and
generation of abnormal noise can be suppressed.
[0519] Further, according to this embodiment, the developing unit 109 can
maintain the separated position only by the spacer 15IR (15IL) of the process
cartridge 100. Therefore, the total component tolerance can be eased and the
spacing amount can be minimized by reducing the number of portions which may
cause variations in the spacing amount between the developing roller 106 and the photosensitive drum 104. Since the amount of separation can be reduced, when the process cartridge 100 is placed in the image forming apparatus main assembly
170, the occupying space of the developing unit 109 at the time when the
developing unit 109 is moved between the contact position and the separated
position becomes smaller, and therefore, the image forming apparatus can be downsized. In addition, since the space of the developer accommodating
portion 29 of the developing unit 109 in which the movement between the contact
position and the separation position occurs can be increased, a downsized and
large-capacity process cartridge 100 can be placed in the image forming
apparatus main assembly 170.
[0520] Further, according to this embodiment, the movable member 152R (152L) is located at the accommodated position when the process cartridge 100 is
mounted, and the developing unit can maintain the spaced position by the spacer
151R (15IL) of the process cartridge 100. Therefore, when the process
cartridge 100 is mounted in the image forming apparatus main assembly 170, the mounting of the process cartridge 100 can be completed by moving only in one
direction. Therefore, it is not necessary to move the process cartridge (tray 171)
both in the upward and downward directions. In addition, the image forming
apparatus main assembly does not require an extra space, and the main assembly
can be downsized. Further, since the spacing amount can be reduced, when the
process cartridge 100 is arranged in the image forming apparatus main assembly
170, the occupying zone of the developing unit 109 at the time when the
developing unit 109 moves between the contact position and the separated
position can be reduced, so that the image forming apparatus can be downsized.
In addition, since the space of the developer accommodating portion 29 of the
developing unit 109 which moves between the contact position and the separated
position can be increased, the downsized and large-capacity process cartridge 100 can be placed in the image forming apparatus main assembly 170.
[0521] In this embodiment, the structure is such that the developing unit 109 is
moved in the arrow V2 direction (direction of movement from the separated
position to the development position) by the driving torque of the development
coupling portion 132a received from the image forming apparatus main assembly
170 and the urging force of the development pressure spring 134. However, as a
structure for urging the developing unit in the V2 direction, it is also possible to
utilize the gravity applied to the developing unit 109. That is, the structure may
be such that the gravity applied to the developing unit 109 is produce a moment
which rotates the developing unit 109 in the V2 direction. In the case of
employing such an urging structure in the V2 direction by its own weight, the
urging structure using the development pressure spring 134 may not be provided,
or may be used in combination with the urging structure using the development
pressure spring 134.
[Details of arrangement of separation/contact mechanisms 150R and 150L]
[0522] Subsequently, referring to Figures 40 and 41, the arrangement of the
separation/contact mechanisms 150R and 150L in this embodiment will be
described in detail. Figure 40 is an enlarged view of the periphery of the spacer
151R as the process cartridge 100 is viewed from the drive-side along the swing
axis K (photosensitive drum axis direction) of the developing unit 109. In
addition, for better illustration, it is a sectional view in which a portion of the
development cover member 128 and a portion of the drive-side cartridge cover
member 116 are partially omitted by the partial cross-sectional line CS. Figure
41 is an enlarged view of the periphery of the spacer 151R as the process
cartridge 100 is viewed from the non-drive-side along the swing axis K
(photosensitive drum axis direction) of the developing unit 109. In addition, for
better illustration, it is a sectional view in which a portion of the development cover member 128 and a portion of the drive-side cartridge cover member 116 are partially omitted by the partial cross-sectional line CS. Regarding the arrangement of the spacer and the movable member, which will be described below, there is no distinction between the drive-side and the non-drive-side except for the part which will be described in detail hereinafter, and the description of the non-drive-side (Figure 41) is omitted, because the non-drive side has a similar structure.
[0523] As shown in Figure 40, a straight line passing through the rotation axis M1 of the photosensitive drum 104 (point M1 in Figure 40) and the rotation axis
M2 of the developing roller 106 (point M2 in Figure 40) is line N. In addition, the contact region between the contact surface 151Rc of the spacer 151R and the
contacted surface 116c of the drive-side cartridge cover member 116 is M3, and the contact region between the pressed surface 151Re of the spacer 151R and the
spacer pressing surface 152Rr of the movable member 152R is M4. Further, the
distance between the swing axis K and the point M2 of the developing unit 109 is distance e, the distance between the swing axis K and the region M3 is distance
e2, and the distance between the swing axis K and the point M4 is distance e3.
[0524] In the structure of this embodiment, when the developing unit 109 is in the separated position and the movable member 152R (152L) is in the projecting
position, the positional relationship is as follows, as the developing unit 109 is
viewed along the swing axis K (or the rotation axis M1 or the rotation axis M2).
That is, as viewed along the swing axis K as shown in Figure 40, at least a part of the contact region M3 is disposed in an region AD1 which is opposite to an
region AUl in which the center (swing axis K) of the development coupling
portion 132a exists, when the region is divided with the line N as a boundary. In
other words, the contact surface 151Rc of the spacer 151R is placed such that the
distance e2 is longer than the distance el. Further, as shown in Figure 40, when the region is divided with the line N as a boundary, at least a portion of the projecting portion 152Rh is placed in the region AD Iopposite to the region AUl in which the center of the development coupling portion 132a (swing axis K) exist, as viewed along the swing axis K. The vertical direction in the attitude shown in Figure 40 (Figure 41), is the vertical direction in the actual attitude at the time when it is mounted to the image forming apparatus main assembly 170.
This attitude can be said to be an attitude in which the rotation axis M1 of the
photosensitive drum 104 is horizontal and the photosensitive drum 104 is placed
at the lower portion in the process cartridge 100. In such an attitude, the region
AD Icorresponds to the lower portion of the process cartridge 100, and is also the
region including the lower portion of the process cartridge 100.
[0525] By arranging the spacer 151R and the contact surface 151Rc in this
manner, it is possible to suppress variations in the attitudes of the separation
positions of the developing unit 109, even when the positions of the contact
surface 151Re vary due to component tolerances and the like. That is, the
influence of the variation of the contact surface 151Rc on the spacing amount
(gap) P1 (see part (a) of Figure 1 between the developing roller 106 and the
photosensitive drum 104 can be minimized, and the developing roller 106 and the
photosensitive drum 104 can be spaced from each other with high precision.
Further, it is not necessary to provide an extra space for retraction when the
developing unit 109 is moved for the spacing, which leads to the of the
downsizing of image forming apparatus main assembly 170.
[0526] Further, the first force receiving portion 152Rk (152Lk) and the second
force receiving portion 152Rn (152Ln), which are the force receiving portions of
the movable member 152R (152L), are disposed on the opposite side of the side
including the rotation center (rotation axis) of the development coupling portion
132a with respect to line N and. That is, at least a portion of each of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) is arranged in the region
AD Opposite to the region AUl in which the rotation center (rotation axis) K of
the development coupling 132a is placed.
[0527] As described above, the projecting portion (force receiving portion)
152Rh (152Lh) is disposed at the end portion in the longitudinal direction.
Further, as shown in Figure 15 (Figure 16), a cylindrical portion 128b (127a),
which is a support portion of the developing unit 109, is disposed at the end
portion in the longitudinal direction. Therefore, the force receiving portion
152Rh (152Lh) including the first force receiving portion 152Rk (152Lk) and the
second force receiving portion 152Rn (152Ln) is disposed on the opposite side of
the side including the cylindrical portion 128b (127a) (that is, the swing axis K)
of the developing unit 109 with respect to the line N, so that the functional
portions can be arranged efficiently. That is, it leads to downsizing of the
process cartridge 100 and the image forming apparatus M. More specifically,
when the region is divided by the straight line N as viewed in the direction along
the rotation axis M2, the structure such as the cylindrical portion 128b (127a) for
movably (relative to the developing unit 109) supporting the drum unit 108 is
placed in the region AUl where the swing axis K is placed. Therefore, at least a
portion of each of the force receiving portions 152Rk (152Lk) and 152Rn
(152Ln) is arranged in the region AD1 in which the development coupling
portion 132a is not arranged in the region AUl in which the swing axis K is
arranged. It is possible to obtain an efficient layout that avoids interference
between the members. This is contributable to downsizing of the process
cartridge 100 and the image forming apparatus M.
[0528] In addition, the force receiving portion 152Rh (152Lh) is disposed at
the end portion on the drive-side in the longitudinal direction. Further, as shown
in Figure 15, a development drive input gear 132 (or a development coupling portion 132a) which receives a drive from the image forming apparatus main assembly 170 and drives the developing roller 106 is provided at the end (with respect to the longitudinal direction) portion on the drive-side. As shown in
Figure 40, the first force receiving portion 152Rk and the second force receiving
portion 152Rn of the movable member is placed on the side opposite from the
side in which the rotation axis K of the development drive input gear 132
(development coupling portion 132a) shown by the broken line, with respect to
extension line of the line N With this arrangement, the functional portions can be
efficiently arranged. That is, it leads to downsizing of the process cartridge and
the image forming apparatus M. More specifically, when the region is divided
by a straight line N as viewed in the direction along the rotation axis M2, in the
region AUl where the development coupling portion 132a exist, the driving
member for driving a member included in the developing unit 109, such as the
developing roller 106 such as a development drive input gear 132 is provided.
Therefore, at least a portion of the force receiving portion 152Rh is better
disposed in the region AD Iin which the development coupling portion 132a is
not placed than in the region AUl in which the development coupling portion
132a is placed, from the standpoint of an efficient layout to avoid interference
between the members. This is contributable to downsizing of the process
cartridge and the image forming apparatus M.
[0529] In the above description, the region AUl and the region AD Iare
defined as regions where the swing axis K or the development coupling portion
132a is placed and the region where it is not placed, when the region is divided
by the straight line N, as viewed in the direction along the rotation axis M2.
However, it is possible to use another definition. For example, the regions AUl
and AD Imay be the region where the charging roller 105 or rotation axis (center
of rotation) M5 thereof is provided and the region where it is not provided, when the region is divided by the straight line N, as viewed in the direction along the rotation axis M2.
[0530] Further, Figure 236 is a schematic cross-sectional view of the process
cartridge 100 in the separated state as viewed in the direction along the rotation
axis M2. Referring to Figures 3 and 236, as a further definition, when the
region is divided by a straight line N as viewed in the direction along the rotation
axis M2, the regions AUl and AD Imay be defined as the region in which the
developing blade 130, the proximity point 130d, or the stirring member 129a and
the rotation axis M7 of the stirring member 129a, or the pressed surface 152Rf
are provided, and the reason in which it is not provided. The proximity point
130d is the position closest to the surface of the developing roller 106 of the
developing blade 130.
[0531] In a general electrophotographic cartridge, particularly a cartridge
usable with an in-line layout image forming apparatus, it is relatively difficult to
arrange other members of the cartridge in the region AD1. Further, if at least a
portion of each of the force receiving portions 152Rk (152Lk) and 152Rn
(152Ln) is placed in the region AD1, the apparatus main assembly 170 also has
the following advantage. That is, the separation control member 196R (196L)
of the apparatus main assembly 170 is placed on the lower side of the cartridge
and moves in the substantially horizontal direction (W41 and W42 directions, and
the arrangement direction of the photosensitive drum 104 or the cartridge 100, in
this embodiment) to urge the force receiving portion 152Rh (152Lh). Withsuch
a structure, the separation control member 196R (196L) and driving mechanism
therefor can be formed in a relatively simple structure or a compact structure.
This is particularly remarkable in the in-line layout image forming devices. As
described above, arranging at least a portion of each of the force receiving
portions 152Rk (152Lk) and 152Rn (152Ln) in the region AD Ican be expected to contribute to the downsizing and cost reduction of the apparatus main assembly 170.
[0532] Further, the contact portion between the spacer 15IR and the movable member 152R is placed such that the distance e3 is longer than the distance el.
By this, the spacer 15IR and the drive-side cartridge cover member 116 can be contacted with each other with a lighter force. That is, the developing roller 106
and the photosensitive drum 104 can be stably spaced from each other.
[0533] The arrangement of the separation/contact mechanisms 150R and L described above has been described referring to Figures 40 and 41 showing the
process cartridge 100 in the separation state, but as is apparent in the other
Figures, the same relationship applies in the process cartridge 100 in the contact
state. Figure 235 is a side view (partial cross-sectional view) of the process
cartridge 100 in the contact state as viewed in the direction along the rotation axis
M2. The arrangement of the force receiving portions 152Rk (152Lk) and
152Rn (152Ln) is the same as that described above.
[0534] Further, the direction perpendicular to the straight line Nis VD1. On the drive-side, the movable member 152R and the force receiving portions 152Rk
and 152Rn move between the stand-by position and the operating position by
moving in the ZA direction and the opposite direction thereto relative to the drum
frame and the developing frame. By the movement in the ZA direction and the
opposite direction, the movable member 152R and the force receiving portions
152Rk and 152Rn are moved at least in the VD1 direction. That is, the movable
member 152R and the force receiving portions 152Rk and 152Rn are moved at
least in the VD1 direction between the stand-by position and the operating
position. According to this structure, when the movable member 152R is in the
operating position, the developing unit 109 can be moved between the developing
position and the retracted position by receiving a force from the separation control member 196R at each of the force receiving portions 152Rk and 152Rn.
When the movable member 152R is in the stand-by position, the movable
member 152R and the force receiving portions 152Rk and 152Rn interfere with
the separation control member 196R so that it can be avoided that the process
cartridge 100 cannot be inserted or removed from the apparatus main assembly
170. The same applies to the structure on the non-drive-side.
[0535] Further, when the movable member 152R is in the operating position,
the projecting portion 152Rh provided with the respective force receiving
portions 152Rk and 152Rn is disposed at a position such that they are projected
from the developing unit 109 in at least the VD1 direction. Therefore, it is
possible to arrange the projecting portion 152Rh in the space 196Rd between the
first force application surface 196Ra and the second force application surface
196Rb of the separation control member 196R. The same applies to the
structure on the non-drive-side.
[Details of arrangement of separation contact mechanisms 150R and 150L (Part
2)]
[0536] Referring to Figures 236 and 237, a concept similar to the concept of
placing at least a portion of each of the force receiving portions 152Rk (152Lk)
and 152Rn (152Ln) in the region AD Ias described above will be described.
[0537] Figures 236 and 237 are schematic cross-sectional views of the process
cartridge 100 as viewed from the drive-side along the rotation axis M1, the
rotation axis K, or the rotation axis M2 of the developing unit 109, Figure 236
shows a separated state, and Figure 237 shows a contact state. Regarding the
arrangement of the spacer 151 and the movable member 152 described below,
there is no difference between the drive-side and the non-drive-side, that is, both
are common, and the contact state and the separation state are almost common,
and therefore, only the separated state on the drive-side will be described referring to Figure 236, and the description on the non-drive-side and the description on the contact state will be omitted.
[0538] The rotation axis of the toner feeding roller (developer supply member)
107 is the rotation axis (rotation center) M6. Further, the process cartridge 100
is provided with a stirring member 108 for rotating and stirring the developer
contained in the developing unit 109, and the rotation axis thereof is the rotation
axis (rotation center) M7.
[0539] In Figure 236, the one, which is farther from the rotation axis M5, of
the intersections of the straight line N10 connecting the rotation axis M1 and the
rotation axis M5 and the surface of the photosensitive drum 104 is the
intersection MX1. The tangent line to the surface of the photosensitive drum
104 passing through the intersection MX1 is a tangent line (predetermined
tangent line) N11. The region is divided by the tangent line Ni1 as a boundary,
and a region containing the rotation axis M1, the charging roller 105, the rotation
axis M5, the developing roller 106, the rotation axis M2, the development
coupling portion 132a, the rotation axis K, the developing blade 130, the
proximity point 130d, and the toner feeding roller 107, the rotating axis M6, the
stirring member 129a, the rotating axis M7, or the pressed surface 152Rf is an
region AU2, and the region not containing it is an region (predetermined region)
AD2. Further, the regions AU2 and AD2 may be defined in another way as
follows. That is, assuming that the direction parallel to the direction from the
rotation axis M5 to the rotation axis M1 and orientating the same is a VD10
direction, the most downstream portion of the photosensitive drum 104 in the
VD1O direction is the intersection MX1. Then, with respect to the direction
VD10, the region on the upstream side of the most downstream portion MX1 is
the region AU2, and the region on the downstream side is the region
(predetermined region) AD2. Regardless of the expression, the defined regions
AU2 are the same, and the regions AD2 are the same.
[0540] Then, at least parts of each force receiving portion 152Rk and 152Rn
are arranged in the region AD2. As described above, arranging at least parts of
each of the force receiving portions 152Rk and 152Rn in the region AD2 can be
expected to contribute to the downsizing and cost reduction of the process
cartridge 100 and the apparatus main assembly 170. This is for the same reason
as in the case that at least a part of each of the force receiving portions 152Rk and
152Rn is arranged in the region AD1. The same applies to the structure on the
non-drive-side.
[0541] Further, the movable member 152R and the force receiving portions
152Rk and 152Rn are displaced at least in the VD10 direction by moving in the
ZA direction and the opposite direction. That is, the movable member 152R and
the force receiving portions 152Rk and 152Rn are displaced at least in the VD10
direction between the stand-by position and the operating position. According
to this structure, when the movable member 152R is in the operating position, the
developing unit 109 can be moved between the developing position and the
retracting position by receiving a force from the separation control member 196R
at each of the force receiving portions 152Rk and 152Rn. When the movable
member 152R is in the stand-by position, it can be avoided that the movable
member 152R and the force receiving portions 152Rk and 152Rn interfere with
the separation control member 196R so that the process cartridge 100 cannot be
inserted or removed from the apparatus main assembly 170. The same applies
to the structure on the non-drive-side.
[0542] Further, the projecting portion 152Rh provided with the respective
force receiving portions 152Rk and 152Rn is disposed at a position such that it is
projected from the developing unit 109 in at least the VD10 direction, when the
movable member 152R is in the operating position. Therefore, it is possible to dispose the projecting portion 152Rh in the space 196Rd between the first force application surface 196Ra and the second force application surface 196Rb of the separation control member 196R. The same applies to the structure on the non drive-side.
[Details of arrangement of separation/contact mechanisms 150R and 150L (Part
3)]
[0543] A concept similar to the concept of arranging at least a portion of each
of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) in the region
AD Ias described above will be described referring to Figure 238.
[0544] Figure 238 is a schematic sectional view of the process cartridge 100 in
the separated state as viewed from the drive-side along the rotation axis M1, the
rotation axis K, or the rotation axis M2 of the developing unit 109. Regarding
the arrangement of the spacer 151 and the movable member 152 described below,
there is no difference between the drive-side and the non-drive-side, and both are
common, and the contact state and the separated state are substantially the
common. Therefore, only the separated state on the drive-side will be described
referring to Figure 238, and the description on the non-drive-side and the
description in the contact state will be omitted.
[0545] In Figure 238, of the intersection of the straight line N12 connecting
the rotation axis K and the rotation axis M2 and the surface of the developing
roller 106, the one farther from the rotation axis K, is defined as the intersection
MX2. The tangent line to the surface of the developing roller 106 passing
through the intersection MX2 is a tangent line (predetermined tangent line) N13.
The region is divided with the tangent line N13 as a boundary, and the part in
which the development coupling portion 132a, the rotation axis K, the rotation
axis M2, the charging roller 105, the rotation axis M5, the developing blade 130,
the proximity point 130d, the toner feeding roller 107, the rotation axis M6, the stirring member 129a, the rotation axis M7, or the pressed surface 152Rf exists is a region AU3, and the region it does not exist is a region (predetermined region)
AD3. Further, the regions AU3 and AD3 may be defined in another way as
follows. That is, the direction parallel to the direction from the rotation axis K
to the rotation axis M2 and orientating the same is a VD12 direction, the most
downstream portion of the developing roller 106 in the VD12 direction is the
intersection MX2. Then, in the VD12 direction, the region on the upstream side
of the most downstream portion MX2 is the region AU3, and the region on the
downstream side is the region (predetermined region) AD3. The regions AU3
and AD3 defined in any of the above expressions are the same, respectively.
[0546] Then, at least a part of each force receiving portion 152Rk and 152Rn
is arranged in the region AD3. As described above, arranging at least a part of
each of the force receiving portions 152Rk and 152Rn in the region AD3 can be
expected to contribute to the downsizing and cost reduction of the process
cartridge 100 and the apparatus main assembly 170. This is for the same reason
as when at least a part of each of the force receiving portions 152Rk and 152Rn is
arranged in the region AD1. The same applies to the structure on the non-drive
side.
[0547] Further, the movable member 152R and the force receiving portions
152Rk and 152Rn are displaced at least in the VD12 direction by moving in the
ZA direction and the opposite direction thereto. That is, the movable member
152R and the force receiving portions 152Rk and 152Rn are displaced at least in
the VD12 direction to move between the stand-by position and the operating
position. According to this structure, when the movable member 152R is in the
operating position, the developing unit 109 can be moved between the developing
position and the retracting position by receiving a force from the separation
control member 196R at each of the force receiving portions 152Rk and 152Rn.
When the movable member 152R is in the stand-by position, it can be avoided
that the movable member 152R and the force receiving portions 152Rk and
152Rn interfere with the separation control member 196R with the result that the
process cartridge 100 cannot be inserted or removed from the apparatus main
assembly 170. The same applies to the structure on the non-drive-side.
[0548] Further, the projecting portion 152Rh provided with the respective force receiving portions 152Rk and 152Rn is disposed at a position such that it is
projected from the developing unit 109 in at least the VD12 direction, when the
movable member 152R is in the operating position. Therefore, it is possible to
place the projecting portion 152Rh in the space 196Rd between the first force
application surface 196Ra and the second force application surface 196Rb of the
separation control member 196R. The same applies to the structure on the non
drive-side.
[Details of arrangement of separation/contact mechanisms 150R and 150L (Part
4)]
[0549] A concept similar to the concept of placing at least a part of each of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) in the region AD Ias
described above will be described referring to Figure 239.
[0550] Figure 239 is a schematic cross-sectional view of the process cartridge 100 in the separated state as viewed from the drive-side along the rotation axis
M1, the rotation axis K, or the rotation axis M2 of the developing unit 109.
Regarding the arrangement of the spacer 151 and the movable member 152
described below, there is no distinction between the drive-side and the non-drive
side, and both are common, and the contact state and the separated state are
substantially common, and therefore, in the following description, only the
separated state on the drive-side will be described referring to Figure 239, and the
description on the non-drive-side and the description in the contact state will be omitted.
[0551] In Figure 239, of the intersection of the straight line N14 connecting
the rotation axis M2 and the rotation axis M6 and the surface of the developing
roller 106, the one which is more remote from the rotation axis K, is the
intersection MX2. The tangent line to the surface of the developing roller 106
passing through the intersection MX2 is a tangent line (predetermined tangent
line) N14. When the region is divided by the tangent line N14 as the boundary,
the region in which the development coupling portion 132a, the rotation axis K,
the charging roller 105, the rotation axis M5, the developing blade 130, the
proximity point 130d, the stirring member 129a, the rotation axis M7, or the
pressed surface exists is the region AU4, and the region in which it does not exist
is the region (predetermined region) AD4.
[0552] At least a portion of each force receiving portion 152Rk and 152Rn is
arranged in the region AD4. As described above, arranging at least a part of
each of the force receiving portions 152Rk and 152Rn in the region AD4 can be
expected to contribute to the downsizing and cost reduction of the process
cartridge 100 and the apparatus main assembly 170. This is for the same reason
as when at least a part of each of the force receiving portions 152Rk and 152Rn is
arranged in the region AD1. The same applies to the structure on the non-drive
side.
[0553] Further, the movable member 152R and the force receiving portions
152Rk and 152Rn are displaced at least in the VD14 direction perpendicular to
the straight line N14 by the movement in the ZA direction and the opposite
direction. That is, the movable member 152R and the force receiving portions
152Rk and 152Rn are displaced at least in the VD14 direction to move between
the stand-by position and the operating position. According to this structure,
when the movable member 152R is in the operating position, the developing unit
109 can be moved between the developing position and the retracted position by
receiving a force from the separation control member 196R at each of the force
receiving portions 152Rk and 152Rn. When the movable member 152R is in
the stand-by position, it can be avoided the movable member 152R and the force
receiving portions 152Rk and 152Rn interfere with the separation control
member 196R with the result that the process cartridge cannot be inserted or
removed from the apparatus main assembly 170. The same applies to the
structure on the non-drive-side.
[0554] Further, when the movable member 152R is in the operating position, the projecting portions 152Rh provided on the respective force receiving portions
152Rk and 152Rn are disposed at positions such that they are projected from the
developing unit 109 in at least the VD14 direction. Therefore, it is possible to
arrange the projecting portion 152Rh in the space 196Rd between the first force
application surface 196Ra and the second force application surface 196Rb of the
separation control member 196R. The same applies to the structure on the non drive-side.
[0555] The arrangement relationship of each force receiving portion described above has the same relationship in all the examples described below.
[Holding mechanism]
[0556] In the above-described embodiment, the structure for the drum unit 108
to stably hold the developing unit 109 at the retracted position and the developing
position is a holding member holding the spacer 151R capable of taking the first
position and the second position or a holding portion holding the separation
holding portion 151Rb which is apart thereof. However, it is also possible to
deem the structure of this embodiment as follows. That is, as a holding
mechanism in which the drum unit 108 stably holds the developing unit 109 at
the retracted position and the developing position, at least the spacer 151R, it is possible to raise the first supporting portion 128c of the development cover member 128, and the contacted surface 116c of the drive-side cartridge cover member 116 and the development pressure spring 134. Insuchacase,itcan be said that the holding mechanism is in the first state when the spacer 151R is in the first position and the developing unit 109 is in the retracted position, and the holding mechanism is in the second position when the spacer 151R is in the second position and the developing unit 109 is in the developing position.
<Embodiment 2>
[0557] Next, referring to Figures 42 to 46, the Embodiment 2 will be
described. In this embodiment, structures and operations different from those in
the above-described embodiment will be described, and members including the
same structures and functions will be assigned the same reference numbers, and
the description thereof will be omitted. In an Embodiment 1, the
separation/contact mechanism 150R and the separation/contact mechanism 150L
are provided as the separation/contact mechanism on the drive-side and the non
drive-side, respectively. On the other hand, in the embodiment, a structure in
which the separation/contact mechanism is provided only on one side of the
process cartridge will be described.
[0558] Figures 42 to 46 are illustrations showing a state when the developing
unit 109 is in the separated position and the movable member of the
separation/contact mechanism is in the projecting position. Part (a) of Figure 42
is a perspective view of the process cartridge 100 of the Embodiment 1 as viewed
from below on the drive-side. Part (b) of Figure 42 is a schematic view
illustrating the amount of spacing of the developing roller 106 from the
photosensitive drum 104 of the process cartridge 100 of Embodiment 1.
[0559] As shown in Figure 42, the spacing amount P1 of the Embodiment 1 is set to be the same amount on the drive-side and the non-drive-side. The spacing amount P1 can be changed by changing the distance nI from the swing axis H of the spacer 151 to the contact surface 151Rc. In this embodiment shown below, the spacing amount is changed with the same structure.
[0560] In the embodiment shown in Figure 43 of this embodiment, the separation/contact mechanism 250-1 of the process cartridge 200-1 is arranged
only on the drive-side, and the separation/contact mechanism is not provided on
the non-drive-side. Part (a) of Figure 43 is a perspective view of the process
cartridge 200-1 as viewed from below on the drive-side. Part (b) of Figure 43 is
a schematic view illustrating the amount of spacing of the developing roller 106
from the photosensitive drum 104 of the process cartridge 200-1.
[0561] As shown in Figure 43, since the separation/contact mechanism 250-1 is arranged only on the drive-side, the spacing amount P2-IL on the non-drive
side is smaller than the amount P2-IR on the drive-side because of the influence
of the development pressure spring (not shown in Figure 43, see 134 in Figure
34). Here, the spacing amount P2- IR on the drive-side is selected so as to be larger than the spacing amount P1 (see part (b) of Figure 42) in Embodiment 1 so
that the spacing amount P2-IL on the non-drive-side does not become 0, that is,
the developing roller 106 and the photosensitive drum 104 do not contact each
other on the non-drive-side.
[0562] By doing so, the same effect as in Example 1 can be provided. In addition, since there is no separation/contact mechanism on the non-drive-side,
the process cartridge and the image forming apparatus main assembly can be
downsized and the cost can be reduced accordingly.
[0563] Figure 44 shows another example 1 of this embodiment. In this
example, the separation/contact mechanism 250-2 of the process cartridge 200-2
is provided only on the drive-side, and there is not provided separation/contact mechanism on the non-drive-side. In this example, when the developing unit 109 is in a separated position, the end of the developing roller 106 on the non drive-side is in contact with the photosensitive drum 104. Part (a) of Figure 44 is a perspective view of the process cartridge 200-2 as viewed from below on the drive-side. Part (b) of Figure 44 is a schematic view illustrating the amount of spacing of the developing roller 106 from the photosensitive drum 104 of the process cartridge 200-2.
[0564] As contrasted to the example shown in Figure 43, in the example of Figure 44, the spacing amount P2-2R on the drive-side is selected so as to be
equal to or smaller than the spacing amount P1 of Embodiment 1. In this case, the developing roller 106 and the photosensitive drum are in contact with each
other on the non-drive-side due to the urging force of the development pressure
spring (not shown in Figure 43, see 134 in Figure 34). However, if the contact
range m2 on the non-drive-side is set out of the range of the image forming
region m4, the image is not affected adversely. Nevertheless, if the effect on the image is so small that it can be ignored, or in the case of the usage in which the
affect, if any, on the image can be ignored, the contact range m2 is not
necessarily set out of the image forming range m4. That is, in such a case, the
contact range m2 may be set within the image forming range m4.
[0565] As described above, in this example, by reducing the spacing amount
as compared with the embodiment shown in Figure 43, it is possible to the
downsizing of the image forming apparatus as described in the Embodiment 1.
In addition, since there is no separation/contact mechanism on the non-drive-side,
the process cartridge and the image forming apparatus main assembly can be
downsized and the cost can be reduced.
[0566] Figure 45 shows another example 2 of this embodiment. In this embodiment, the separation/contact mechanism 250-1 of the process cartridge
200-3 is provided only on the non-drive-side, and there is no separation/contact
mechanism on the drive-side. Part (a) of Figure 45 is a perspective view of the
process cartridge 200-3 as viewed from below on the non-drive-side. Part (b) of
Figure 45 is a schematic view illustrating the amount of spacing of the
developing roller 106 from the photosensitive drum 104 of the process cartridge 200-3.
[0567] As shown in Figure 45, since the separation/contact mechanism 250-3 is provided only on the non-drive-side, the spacing amount P2-3R on the drive
side is smaller than the spacing amount P2-3L on the non-drive-side by the
influence of the drive input gear (not shown in Figure 45, see 132a in Figure 1).
Here, the spacing amount P2-3L on the non-drive-side is selected so as to be
large than the spacing amount P1 in Embodiment 1 so that the spacing amount
P2-3R on the drive-side does not become 0, that is, the developing roller 106 and
the photosensitive drum 104 do not contact each other on the drive-side.
[0568] By doing so, the same effect as in Example 1 can be provided. In
addition, since there is no separation/contact mechanism on the drive-side, the
process cartridge and the image forming apparatus main assembly can be
downsized and the cost can be reduced.
[0569] Figure 46 shows further example 3 of this embodiment. In this embodiment, the separation/contact mechanism 250-4 of the process cartridge
200-4 is provided only on the non-drive-side, and no separation/contact
mechanism is provided the drive-side. Further, when the developing unit 109 is
in a separated position, the end portion of the developing roller 106 on the drive
side and the photosensitive drum 104 are provided. Part (a) of Figure 46 is a
perspective view of the process cartridge 200-4 as viewed from below on the
drive-side. Part (b) of Figure 46 is a schematic view illustrating the amount of
spacing of the developing roller 106 from the photosensitive drum 104 of the process cartridge 200-4.
[0570] Unlike the example of Figure 45, in the example of Figure 46, the
spacing amount P2-4L on the non-drive-side is selected so as to be equal to or
smaller than the spacing amount P1 of the Embodiment 1. In this case, due to
the influence of the drive input gear (not shown in Figure 46, 132a in Figure 1),
the developing roller 106 and the photosensitive drum 104 contact each other on
the drive-side. However, if the contact range m5 on the drive-side is set within
a range which does not fall within the image forming region m4, the image is not
affected. The amount of separation at the drive-side and the non-drive-side can
be arbitrarily set within a range that does not affect the image.
[0571] As described above, by reducing the spacing amount as compared with
the example of Figure 45, it is possible to downsize the image forming apparatus
as described in the Embodiment 1, and also to reduce the cost of the process
cartridge.
[0572] In the four examples described above in this embodiment, the amount
of spacing at the drive-side and the non-drive-side can be arbitrarily set within a
range which does not affect the image.
<Embodiment 3>
[0573] Next, referring to Figures 47 to 55, Embodiment 3 of the present
invention will be described.
[0574] In this embodiment, structures and operations different from those of
the above-described embodiment will be mainly described, and description of
similar structures and operations will be omitted. For the structure
corresponding to that in the above-described embodiments, the same reference
numerals and characters are assigned, or the reference numerals in the first part is
changed while the reference numerals and characters in the second part are the same. In this embodiment, the structure and operation of the movable member are mainly different from those in the Embodiment 1. The spacer 351L has the similar structure as the spacer 151L.
[Structure of movable member]
[0575] First, the structure of the movable member will be described by taking the non-drive-side as an example. Figure 47 is an illustration of disassembly
and assembly of the movable member 352L on the non-drive-side. In
Embodiment 3, the movable member corresponding to the movable member
152L in the Embodiment 1 is divided into two parts and they are connected
together. Specifically, as shown in Figure 47, the movable member 352L is
divided into two parts, namely, an upper movable member 352L1 and a lower
movable member 352L2. A shaft 352L2a is provided on the lower movable
member 352L2. Further, as shown in part (a) of Figure 48, the lower movable
member 352L2 is provided with a projecting portion 352Lh capable of projecting
from the developing unit in the ZA direction, and the projecting portion 352Lh includes a first force receiving portion (retracting force receiving portion,
separating force receiving portion) 352Lk and a second force receiving portion
(contact force receiving portion) 352Ln. The upper movable member 352L1 has
an opening portion 352L1d in a surface opposing the lower movable member
352L2. In addition, the upper movable member 352L1 has an at-separation
pressing portion 352L1q for pressing the non-drive-side bearing 327.
[0576] Further, the upper movable member 352L1 is provided with a pair of oblong round holes 352L1h with an open portion 352L1d interposed
therebetween. The lower movable member 352L2 is provided with a spring
holding portion 352L2b. One end of the compression spring 352Lsp is fitted to
the spring holding portion 352L2b, the other end is inserted from the opening
portion 352L1d to be supported by the holding portion (not shown) at the back thereof, and then shafts 352L2a are inserted into the respective oblong round holes352L1h. At that time, the free end portion 352Lla is assembled while being expanded, and therefore, a plastic material is preferable for the element
352L. In the case that the 352L is made of a hard material, the shafts 352L2a
and 352L2 may be formed separately. For example, the shaft 352L2a may be
finally press-fitted into the shaft 352L2 for the assembling.
[0577] By doing so, the upper movable member 352L1 and the lower movable
member 352L2 are connected with each other by the oblong round hole 352L1h
and the pair of shafts 352L2a, and the upper movable member 352L1 is urged
away from the lower movable member 352L2 by the compression spring 352Lsp.
Further, the lower movable member 352L2 is rotatably structured about the shaft
352L2a relative to the upper movable member 352L1. In addition, it is
structured to be relatively movable in the direction along the oblong round hole
352L1h2 relative to the upper movable member 352L1.
[Description of operation of movable member]
[0578] Next, referring to part (a) of Figure 48 to part (d) of Figure 48, the
operation of the movable member 352L will be described. As described in the
Embodiment 1, after the process cartridge 300 is completely inserted into the
image forming apparatus main assembly 170, the movable member 352L is
pressed by the cartridge pressing unit 190 in interrelation with the operation of
closing the front door 11. The operation of the movable member 352L at that
time will be described.
[0579] Part (a) of Figure 48 and part (b) of Figure 48 show a state in which the
movable member 352L is not urged by the cartridge pressing mechanism 190
(free state), and part (c) of Figure 48 and part (d) of Figure 48 show a state
(locked state) in which the movable member 352L is urged by the cartridge
pressing mechanism 190.
[0580] First, referring to part (a) of Figure 48 and part (b) of Figure 48, the
description will be made as to a state in which the movable member 352L is not
urged by the cartridge pressing mechanism 190 (free state). As shown in part
(b) of Figure 48, a groove is formed between the arcuate guide ribs 327gl and
327g2 extending arcuately about the swing axis HE of the non-drive-side bearing
327, and the shaft 352L2a fits in the groove.
[0581] The upper movable member 352L1 is movable in the longitudinal
direction and the ZA direction of the oblong round hole and swingable around the
axis HE, by fitting the oblong round hole 352L1h2 into the axis HE of the bearing
327. As described above, the lower movable member 352L2 can swing about
the shaft portion 352L2a relative to the upper movable member 352L1. The
cartridge pressing mechanism 190 urging the upper movable member 352L1, the
upper movable member 352L1 can approach to the lower movable member
352L2.
[0582] With the above structure, in the state where the movable member 352L
is not urged by the cartridge pressing mechanism 190 (free state) a, the lower
movable member 352L2 can swing in the directions of arrows Ou and Ou' with a
radius Rx about the shaft portion 352L2a as the center of rotation, as shown in
part (a) of Figure 48. Therefore, even if the first force receiving portion
(retracting force receiving portion, the separating force receiving portion) 352Lk
and the second force receiving portion (contact force receiving portion) 352Ln of
the lower movable member 352L2 receive the force to swing in the directions of
arrows Ou and Ou', the force urging the non-drive-side bearing 327 of the upper
movable member 352L1 is not transmitted to the at-separation pressing portion
352L1q.
[0583] Next, referring to part (c) of Figure 48 and part (d) of Figure 48, the
operation of the movable member 352L in the state of being urged by the cartridge pressing mechanism 190 (locked state) will be described. By pushing down the upper movable member 352L1 by the cartridge pressing mechanism
190, the upper movable member 352L1 moves toward the lower movable
member 352L2 against the urging force of the spring 352Lsp, and as shown in
part (c) of Figure 48, part (d) of Figure 48 and Figure 57, the engaging portion
(square shaft portion) 352Lla is fitted into the engaged portion (square hole
portion) 352L2h, and the upper movable member 352L1 and the lower movable
member 352L2 are made integral. That is, the lower movable member 352L2
becomes in a state in which the swinging around the shaft portion 352L2a relative
to the upper movable member 352L1 is restricted. In this state, as shown in part
(c) of Figure 48, the integrated movable member 352L can swing in the directions
of arrows Ow and Ow with the turning radius Ry shown in part (c) of Figure 48,
while the shaft 352L2a moves about the movable member swinging axis HE
along the formed groove formed between the arcuate guide ribs 327gl and 327g2
shown in part (d) of Figure 48. Although the details will be described
hereinafter, in the state of being pushed by the cartridge pressing mechanism 190,
the movable member 352L can make the same movement as the movable
member 152L in Embodiment 1.
[0584] Further, in a state where it is not urged by the pressing mechanism 190,
the lower movable member 352L2 can swing with a turning radius Rx (see part
(a) of Figure 48 smaller than the turning radius Ry described above.
[0585] The spacer (holding member) 351L is urged to rotate clockwise to the
portion 351Lf by the urging member 153 (not shown for simplicity in this
embodiment) by the same structure as that of the Embodiment 1.
[Mounting of process cartridge to image forming apparatus main assembly]
[0586] Next, referring to part (a) of Figure 49 to part (d) of Figure 49, the
operation of the movable member 352L when the process cartridge is inserted in the Embodiment 3 will be described. Part (a) of Figure 49 shows a state in which the process cartridge 300 is being inserted into the image forming apparatus main assembly 170. Part (b) of Figure 49 shows a state in which the process cartridge 300 is being taken out of the image forming apparatus main assembly 170. Part (c) of Figure 49 shows a state immediately after the process cartridge 300 is completely inserted into the image forming apparatus main assembly 170.
[0587] As described above, in the state where the upper movable member
352L1 is not pushed (free state), the lower movable member 352L2 can swing
around the shaft portion 352L2a as shown in part (e) of Figure 49. In this
embodiment, the lower movable member 352L2 is in the same position as the
constantly projecting position (see Figure 35) of the movable member in the
Embodiment 1. Therefore, when the process cartridge 300 mounted on the
cartridge tray 171 (not shown) is inserted into the image forming apparatus main
assembly 170 in the direction of the arrow X1 as in the Embodiment 1, the
separation control member 196L and the lower movable member 352L2 interfere
with each other.
[0588] However, because of the above-described structure, as shown in part
(a) of Figure 49, it can be avoided that the lower movable member 352L2 swings
in the direction of arrow Ou about the shaft portion 352L2a as the center of
rotation, with the result that the separation control member 196L and the lower
movable member 352L2 interfere with each other, thus preventing it from being
inserted into the main assembly 170.
[0589] At this time, the lower movable member 352L2 presses the spacer
351L by swinging in the direction of the arrow Ou to move the spacer 351L from
the separation holding position to the separation release position, so that the
developing unit 109 moves to the developing position (contact position).
However, after that, when the power of the image forming apparatus main
assembly 170 is turned on, the separation control member 196L reciprocates in
the W42 direction and the W41 direction, and therefore, the developing unit 109
returns to the separating position (retracted position) again when the preparation
for the image formation preparation is completed.
[0590] Further, as shown in part (a) of Figure 50, the lower movable member
352L2 comes into contact with the separation control member 196L in a state
where the cartridge tray 171 is completely inserted into the apparatus main
assembly 170, with the result that the state shown in part (b) of Figure 50 is not
reached and it stops at a position partway. Referring to Figures 50 and 51, a
method for surely avoiding such a state will be described.
[0591] First, as shown in part (a) of Figure 51, the upper movable member
352L1 is provided with a projection 352L1p functioning as a rotation assisting
portion. Further, the lower movable member 352L2 is provided with a slope
352L2s. When the upper movable member 352L1 descends, the projection
352L1p comes into contact with the slope 352L2s to rotate the lower movable
member 352L2 in the direction of the arrow Ou. By doing so, as shown in part
(a) of Figure 50, the lower movable member 352L2 rotates in the direction of
arrow Ou, and while pushing down the separation control member 196L in the
direction of arrow Ou, it rotates to the position shown in part (b) of Figure 50.
[0592] Next, when the process cartridge 300 is inserted into the image forming
apparatus main assembly 170 and the front door 11 is closed, the movable
member 352L is pushed down in the direction of ZA by the cartridge pressing
mechanism 190 (Figure 37 and the like) as described in the foregoing by the
arrow shown in part (a) of Figure 52. Then, as shown in part (b) of Figure 52,
the engaging portion (square shaft portion) 352L la fits into the engaged portion
(square hole portion) 352L2h. That is, the upper movable member 352L1 and the lower movable member 352L2 are made integral, and play the substantially same role as the movable member 152L of the Embodiment 1.
[Dismounting of process cartridge from image forming apparatus main assembly]
[0593] On the contrary, as shown in part (b) of Figure 49, when the process
cartridge 300 is taken out of the main assembly of the image forming apparatus in
the direction of the arrow X2, the separation control member 196L and the lower
movable member 352L2 interfere with each other.
[0594] However, as described above, since the movable member 352L1 is in a
free state, when receiving the force by the first force receiving portion (retracting
force receiving portion, the spacing force receiving portion) 352 Lk, the lower
movable member 352L2 rotates about the shaft portion 352L2a as the center of
rotation in the direction of arrow Ou. However, the force received by the first
force receiving portion (retracting force receiving portion, separating force
receiving portion) 352Lk is not transmitted to the at-separation pressing portion
352L1q which presses the non-drive-side bearing 327 of the developing unit 109
of the upper movable member 352L1. That is, the movable member 352L1
cannot move the developing unit 109. This state is the transmission disabled
state in which the transmission of the pressing force does not occur. Therefore,
it is possible to prevent occurrence of the state that the separation control member
196L and the lower movable member 352L2 interfere with each other with the
result of incapability of removing the it from the apparatus main assembly 170.
In this embodiment, the process cartridge is usable with the color image forming
apparatus. Therefore, there are four process cartridges and four separation
control members. And, depending on the station, the operation shown in Figure
49 may be repeated four times at the maximum.
[0595] The lower movable member 352L2 is structured to return from the
position shown in part (c) of Figure 49, for example, to the neutral position shown in part (d) of Figure 49 (the position in which the upper movable member
352L1 shown in Figure 56 and the lower movable member 352L2 form an angle
Ot (= 0 °) by the restoring force of the compression spring 352Lsp,.
[Contact/separation operations of developing unit]
[0596] Part (a) of Figure 53 shows the moment of contact between the
developing roller 106 and the photosensitive drum 104, part (b) of Figure 53
shows the separating operation of the developing unit 109, and part (c) of Figure
53 shows the details of the movable member 352. The movable member 352L
is in a locked state and can play substantially the same role as the movable
member 152L shown in the Embodiment 1. Therefore, the movable member
352L receives the force from the separation control member 196L and acts on the
spacer 351L to release the separation. The member to be contacted with the
spacer 351L may either be the upper movable member 352L1 or the lower
movable member 352L2. That is, the at-contact pressing portion which presses
the spacer 351L upon the contact operation may be provided on at least one of the
upper movable member 352L1 and the lower movable member 352L2. Further,
in the separating operation, a force is received from the separation control
member 196L, and the at-separation pressing portion 352L1q of the upper
movable member 352L1 integrated with the lower movable member 352L2 is
brought into contact with the shaft portion 327a, so that the entire developing
frame 325 swings. This state is a transmission state in which the force received
by the first force receiving portion 352Lk can be transmitted to the at-separation
pressing portion 352L1q, to move the non-drive-side bearing 237 so as to move
the developing unit 109 from the developing position to the retracted position.
And, the spacer 351L moves through the same operation as in the Embodiment 1
to maintain the separated state.
[Structure of drive-side separation/contact mechanism]
[0597] Figure 54 is an external view illustrating the structure of the drive-side
of the developing unit portion of the process cartridge 300. In this embodiment,
the structure has been described using the separation/contact mechanism on the
non-drive-side, but since the structure on the drive-side is analogous, and
therefore detailed description is omitted. The movable member 352R on the
drive-side is a member corresponding to the movable member 152R in the
Embodiment 1, and has a structure in which the upper movable member 352R1
and the lower movable member 352R2 are connected with each other in the same
manner as with the movable member 352L on the non-drive-side.
[Driving side and non-drive-side separation/contact mechanisms]
[0598] Figure 55 is a perspective view of the process cartridge 300 as viewed
from the developer side. In this embodiment, as shown in part (a) of Figure 55,
the movable member 352L is provided on the non-drive-side, and the movable
member 352R is provided on the drive-side. As another example, as shown in
part (b) of Figure 55, the movable member 352L may be provided only on the
non-drive-side. Further, as shown in part (c) of Figure 55, the movable member
352R may be provided only on the drive-side.
[0599] According to the structure of this embodiment described above, the
same effect as that in the Embodiment 1 can be provided.
[0600] Further, in this embodiment, the lower movable member 352L2
including the first force receiving portion (retracting force receiving portion, the
separating force receiving portion) 352Lk and the second force receiving portion
(contact force receiving portion) 352Ln is movable relative to the upper movable
member 352L1 and other portions of the process cartridge 300. In this
embodiment, by this movement, the first force receiving portion 352Lk and the
second force receiving portion 352Ln are displaced in the ZA direction, by which
it is displaced at least in the direction VD1 (Figure 40, and so on), the direction
VD10 (Figure 236, and so on), and the direction VD12 (Figure 238), and in
direction VD14 (Figure 239). Then, the movable member 352L2 can be
switched between a movable state (free state) and a state fixed to the upper
movable member 352L1 (locked state), depending on the position of the upper
movable member 352L1. By this, it can be avoided that when the process
cartridge 300 is inserted into or removed from the apparatus main assembly 170,
the lower movable member 352L2 and the apparatus main assembly 170,
particularly the separation control member 196L, interfere with each other with
the result of incapability of insertion and removal of the process cartridge.
<Embodiment 4>
[0601] Next, referring to Figure 58 to Figure 66, Embodiment 4 will be
described.
[0602] In this embodiment, structures and operations different from those of
the above- described embodiment will be mainly described, and description of
similar structures and operations will be omitted. For the structure
corresponding to that in the above-described embodiments, the same reference
numerals and characters are assigned, or the reference numerals in the first part is
changed while the reference numerals and characters in the second part are the
same. The spacer 651L has the same structure as the spacer 151L.
[Structure of movable member]
[0603] First, the structure of the movable member will be described by taking
the non-drive-side as an example. Figure 58 is an illustration of disassembly
and assembly of the movable member 652L on the non-drive-side which will be
described in Embodiment 6. In Embodiment 6, as shown in Figure 62, the
movable member corresponding to the movable member 152L in the
Embodiment 1 avoids the interference with the separation control member 196L in the longitudinal direction (Y1, Y2), in the process of inserting and removing the process cartridge 600 into the image forming apparatus main assembly 170.
The directions Y1 and Y2 are parallel to the rotation axis M1 of the
photosensitive drum 104 and the rotation axis M2 of the developing roller 106 of
the Embodiment 1. The insertion/removal of the movable member while
avoiding the separation control member 196L will be described hereinafter.
[0604] As shown in Figure 58, the specific structure of the movable member
652L is a two-divided structure of an upper movable member 652L1 and a lower
movable member 652L2. Part (a) of Figure 58 shows a state before assembling
the upper movable member 652L1 and the lower movable member 652L2. Part
(b) of Figure 58 and part (c) of Figure 58 show the state after the upper movable
member 652L1 and the lower movable member 652L2 are assembled. Inthe
upper movable member 652L1, a pair of oblong round holes 652L1h are provided
so as to oppose each other in the X1 and X2 directions, at the position
overlapping with the lower movable member 652L2 in the direction of inserting
and removing the process cartridge relative to the image forming apparatus main
assembly (Xl, X2 directions, Figure 62). The lower movable member 652L2 is
provided with the shaft 652L2a. Further, as shown in part (a) of Figure 48, the
lower movable member 652L2 is provided with a projecting portion 652Lh
capable of projecting from the developing unit in the ZA direction, and the
projecting portion 652Lh includes a first force receiving portion (retracting force
receiving portion, separating force receiving portion) 652Lk and a second force
receiving portion (contact force receiving portion) 652Ln. A compression
spring 652Lsp is provided between the upper movable member 652L1 and the
lower movable member 652L2. One end of the compression spring 652Lsp is
supported by the upper holding portion 652LId of the upper movable member
652L1, the other end is seated on the seating surface 652L2c of the lower holding portion 652L2b, and then the shaft 652L2a is engaged with the oblong round hole
652L1h.
[0605] When assembling the movable member 652L in this manner so that the
shaft 652L2a fits into the oblong round hole 652L1h, the free end portion 652Lla
of the upper movable member 652L1 is expanded and assembled, so that it is
preferably made of a plastic material. In the case that the movable member
652L is made of a hard material, the shaft 652L2a and the lower movable
member 652L2 may be formed separately. For example, the shaft 652L2a may
be finally press-fitted into the lower movable member 652L2.
[0606] Figure 59 is a perspective view of the upper movable member 652L1
and the lower movable member 652L2 of a two-divided structure (compression
spring 652Lsp is not shown).
The upper movable member 652L1 and the lower movable member 652L2 of
the assembled movable member 652L can take the following two states. One of
them is a state in which the shaft 652L2a of the lower movable member 652L2 is
located at a position away from the upper holding portion 652L1d relative to the
center of the oblong round hole 652L1h of the upper holding portion 652L1d, as
shown in part (b) of Figure 58 andpart (a) of Figure 59. The otheris ina state
where the shaft 652L2a of the lower movable member 652L2 is located close to
the upper holding portion 652L1d relative to the center of the oblong round hole
652L1h of the upper holding portion 652L1d as shown in part (c) of Figure 58
and part (b) of Figure 59.
[0607] In a state where the shaft 652L2a shown in part (b) of Figure 58 and
part (a) of Figure 59 is located away from the upper holding portion 652L1d
relative to the center of the oblong round hole 652L1h, the lower movable
member 652L2 supports only the shaft 652L2a and can swing in the directions of
arrows Y3 and Y4 about the shaft 652L2a (free state), with respect to the upper movable member 652L1. In this free state, the lower movable member 652L2 supports only the shaft 652L2a and is kept swingable with respect to the upper movable member 652L1 by the force of the compression spring 652Lsp provided between the upper holding portion 652L1d of the upper movable member 652L1 and the seating surface 652L2c of the lower holding portion 652L2b.
[0608] In a state where the shaft 652L2a shown in part (c) of Figure 58 and
part (b) of Figure 59 is located close to the upper holding portion 652L1d relative
to the center of the oblong round hole 652L1h, the free end portion 652L la of the
upper movable member 652L1 is in the square hole portion 652L2h, so that the
lower movable member 652L2 is restricted from swinging about the shaft 652L2a
(locked state). This locked state is the state when the upper movable member
652L1 which will be described hereinafter is pressed by the image forming
apparatus main assembly, and the upper movable member 652L1 is integral with
the lower movable member 652L2.
[Description of operation of movable member]
[0609] Next, the operation of the movable member 652L will be described
referring to part (a) of Figure 60 to part (d) of Figure 60. As described in the
Embodiment 1, after the process cartridge 600 is completely inserted into the
image forming apparatus main assembly 170, the movable member 652L is urged
by the cartridge pressing unit 190 in interrelation with the operation of closing the
front door 11. The operation of the movable member 652L at that time will be
described. Part (a) of Figure 60 and part (b) of Figure 61 are in the free state as
described referring to part (b) of Figure 58 and part (a) of Figure 59, in which the
movable member 652L is not urged by the cartridge pressing mechanism in the
image forming apparatus main assembly. Part (c) of Figure 60, Figure(d) and
part (b) of Figure 61 are in the locked state shown in part (c) of Figure 58 and
part (b) of Figure 59, in which the movable member 652L is pushed by the mechanism 190 in the image forming apparatus main assembly.
[0610] Referring to part (a) of Figure 60 and part (b) of Figure 60 first, a state
in which the imparting member 652L is not pressed by the cartridge pressing
mechanism 190 (free state) will be described. In the process cartridge 600, the
upper movable member 652L1 can move in the longitudinal direction and the ZA
direction of the oblong round hole and can swing around the swing shaft HE by
the oblong round hole 652L1h2 fitting around the swinging shaft HE of the
bearing 627. At this time, the lower movable member 652L2 is in a state where
it can swing about the shaft portion 652L2a relative to the upper movable
member 652L1 as described above.
[0611] In this swingable state (free state), the lower movable member 652L2
avoids engagement with the separation control member 196L which engages with
the movable member described in the Embodiment 1 when it is inserted into and
removed from the image forming apparatus main assembly as will be described
hereinafter. For example, as shown in Figure 63 in which the seating surface
652L2c portion shown in part (b) of Figure 60 and part (b) of Figure 60 is
enlarged, the lower movable member 652L2 receives the urging force of the
compression spring 652Lsp by which the state of having swung relative to the
upper movable member 652L lin the Y3 direction is maintained to effect the
avoidance. To accomplish this, the seating surface 652L2c of the lower
movable member 652L2 faces the upper holding portion 652L1d of the upper
movable member 652L1 in a state where the lower movable member 652L2
swings in the Y3 direction. By this, the swung state is maintained by the
moment acting on the lower movable member 652L2 about the shaft portion
652L2a in the Y3 direction so that the seating surface 652L2c faces the upper
holding portion 652L1d by the elastic force of the compression spring 652Lsp
provided between the upper movable member 652L1 and the lower movable member 652L2.
[0612] Next, referring to part (c) of Figure 60 and part (d) of Figure 60, the
operation of the movable member 652L in a state of being urged by the cartridge
pressing mechanism 190 (locked state) will be described.
[0613] By pushing down the cartridge pressing mechanism 190, the upper
movable member 652L1 moves toward the lower movable member 652L2
against the spring 652Lsp. The lower movable member 652L2 is urged in the
direction in which the cartridge pressing mechanism is urged down by the shaft
652L2a coming into contact with the arcuate guide rib 627g of the bearing 627.
Then, as shown in part (c) of Figure 60 part (d) of Figure 60 and part (b) of
Figure 61, the free end portion 652L la of the upper movable member 652L1
which has moved toward the lower movable member 652L2 enters the square
hole portion 652L2h, by which the movable member 652L2 swings around the
shaft 652L2a, and the upper movable member 652L1 and the lower movable
member 652L2 are integrated as described above. In this state, as shown in part
(c) of Figure 60, the integrated movable member 652L swings in the X4 direction
and the X5 direction with the turning radius Rx about the movable member
swinging axis HE as the center of rotation. In this state, when a force is
received by the first force receiving portion (retracting force receiving portion,
separating force receiving portion) 652Lk, the movable member 652L rotates in
the X4 direction so that the at-separation pressing portion 652Lq urges the
arcuate guide rib 627g which is the at-separation urged portion of the bearing 627.
By this, the developing unit 109 can be moved in the direction from the
development position to the retracted position. In this state, when a force is
received by the second force receiving portion (contact force receiving portion)
652Ln, the movable member 652L rotates in the X5 direction, and the at-contact
pressing portion 652Lr urges the at-contact urging portion 621Le of the spacer
651L. By this, the spacer 651L can be moved from the restriction position (first
position) to the permission position (second position). When the movable
member 652L is locked in this manner, it is in a transmittable state in which the
forces received by the first force receiving portion (retracting force receiving
portion, separating force receiving portion) 652Lk and the second force receiving
portion (contact force receiving portion) 652Ln can be transmitted to the at
separation urging portion 652Lq and the at-contact urging portion and the at
contact pressing portion 652Lr.
[0614] Although the details will be described hereinafter, in the state of being
urged by the cartridge pressing mechanism 190, the movable member 652L can
make the same movement as the movable member 152L in the Embodiment 1.
The spacer (holding member) 651L is urged to rotate clockwise by the urging
member 153 (not shown for simplicity in this embodiment) on the 651Lf portion
in the same structure as in the Embodiment 1.
[Mounting of process cartridge to image forming apparatus main assembly]
[0615] Next, referring to part (a) of Figure 62 to part (d) of Figure 62, the
operation of the movable member 652L at the time of inserting the process
cartridge in the Embodiment 6 will be described. Part (a) of Figure 62 is an
illustration showing a state in the process of inserting and removing the process
cartridge 600 into the image forming apparatus main assembly 170, as viewed in
the longitudinal direction. Part (b) of Figure 62 is an illustration showing a state
in which the process cartridge 600 is being inserted and removed from the image
forming apparatus main assembly 170, is viewed in the inserting direction. Part
(c) of Figure 62 is a view illustrating a state in which the process cartridge 600 is
inserted into the image forming apparatus main assembly 170 and the front door
11 is closed, as viewed in the longitudinal direction. Part (d) of Figure 62 is a
view illustrating a state in which the process cartridge 600 is inserted into the image forming apparatus main assembly 170 and the front door 11 is closed, as viewed in the inserting direction. As described above, in the state where the upper movable member 652L1 is not pushed (free state), the lower movable member 652L2 can swing around the shaft portion 652L2a as shown in part (b) of
Figure 58.
[0616] As shown in part (a) of Figure 62 and part (b) of Figure 62, when the
cartridge tray 171 (not shown) loaded with the process cartridge 600 is inserted
into the image forming apparatus main assembly 170 in the direction of arrow X1
or taken out in the direction of arrow X2, it is inserted and removed in a state that
the portion on the free end side of the lower movable member 652L2 with respect
to the control member 196L is in the retraction state in the longitudinal direction
(Y1 direction). This is because the lower movable member 652L2 is held in the
state shown in part (b) of Figure 58 and part (a) of Figure 59 by the action of the
compression spring 652Lsp.
[0617] However, it is not always necessary that the portion of the lower
movable member 652L2 on the free end side is held in a state of being retracted
in the longitudinal direction (Y1 direction). Another structure is shown in
Figure 64. Part (a) of Figure 64 is an illustration showing a state in the process
of inserting and removing the process cartridge 600 relative to the image forming
apparatus main assembly 170 in the longitudinal direction. Part (b) of Figure 64
is an illustration showing a state in which the process cartridge 600 is being
inserted and removed from the image forming apparatus main assembly 170 in
the inserting direction. Part (c) of Figure 64 is a cross-sectional view taken
along the line Q-Q of part (b) of Figure 64. Part (d) of Figure 64 is a Q-Q cross
sectional view of a state in which the process cartridge 600 is further inserted in
the X1 direction from the state of part (c) of Figure 64.
[0618] In an alternative structure shown in Figure 64, the slope 653L2d of the lower movable member 653L2 is brought into contact with the separation control member 196L, thereby to cause to change the state from the state in which the lower movable member 196L and the lower movable member 653L2 are overlapped with each other is viewed in the Y1 and Y2 directions by the force in the insertion/removal directions (X1 and X2 directions) as shown in part (c) of
Figure 64 to the state in which the portion on the free end side of the lower
movable member 652L2 is retracted in the longitudinal direction (Y1 direction),
by the lower movable member 653L2 is brought into contact with the separation
control member 196L shown in part (d) of Figure 64. In this manner, when the
process cartridge 600 is inserted into and removed from the image forming
apparatus main assembly 170, the movable member 652L is in a free state.
[0619] In this embodiment, the process cartridge usable with the color image forming apparatus is described. Therefore, there are four process cartridges and
four separation control members. Therefore, depending on the station, the
operation shown in Figure 62 may be repeated four times at the maximum.
[0620] Next, as shown in part (c) of Figure 62 and part (d) of Figure 62, when the process cartridge 600 is inserted into the image forming apparatus main
assembly 170 and the front door 11 is closed, the movable member 652L is lower
by the cartridge pressing mechanism 190 as described above in the direction of
arrow Z2. By this, the lower movable member 652L2, which has been
swingable, cannot swing relative to the upper movable member 652L1, so that
these are integrated (interlocked state). The movable member in this state
performs substantially the same functions as the movable member 152 in the
Embodiment 1.
[Structure of drive-side separation/contact mechanism]
[0621] Figure 65 is an external view illustrating the structure of the drive-side of the developing unit portion of the process cartridge 600. Figure 66 is a perspective view of the process cartridge 600. In this embodiment, the structure has been described using the separation/contact mechanism on the non-drive-side, but since the structure on the drive-side is similar thereto, detailed description thereof is omitted. The movable member 652R on the drive-side is a member corresponding to the movable member 152R in the Embodiment 1, and has a structure in which the upper movable member 652R1 and the lower movable member 652R2 are connected in the same manner as the movable member 652L on the non-drive-side.
[Driving side, non-drive-side separation/contact mechanism]
[0622] In this embodiment, the movable member 652L is provided in on the
non-drive-side, and the movable member 652R is Provided on the drive-side.
As another example, the movable member 652L may be provided only on the
non-drive-side. Furthermore, the movable member 652R may be provided only
on the drive-side.
[0623] According to the structure of this embodiment described above, the
same effects the gap that as those of the Embodiment 1 can be provided.
[0624] Further, in this embodiment, the lower movable member 652L2
provided with the first force receiving portion (retracting force receiving portion,
separating force receiving portion) 652Lk and the second force receiving portion
(contact force receiving portion) 652Ln is made movable relative to, the upper
movable member 652L1 and other portions of the process cartridge 600. In this
embodiment, by the movement, the first force receiving portion 652Lk and the
second force receiving portion 652Ln is displaced at least in the Y1 direction (the
direction parallel to the rotation axis M1 and the rotation axis M2 of the
Embodiment 1). Then, the lower portion movable member 652L2 can be
switched between a movable state (free state) and a state fixed to the upper
movable member 652L1 (locked state) depending on the position of the upper movable member 652L1. By this, it can be avoided that when the process cartridge 600 is inserted or removed into the apparatus main assembly 170, the lower movable member 652L2 and the apparatus main assembly 170, particularly the separation control member 196L, interfere with each other with the result of incapability of insertion or removal.
<Embodiment 5>
[0625] Next, referring to Figures 67 to 72, Embodiment 5 of the present
invention will be described.
[0626] In this embodiment, structures and operations different from those of
the above-described embodiment will be mainly described, and description of
similar structures and operations will be omitted. For the structure
corresponding to that in the above-described embodiments, the same reference
numerals and characters are assigned, or the reference numerals in the first part is
changed while the reference numerals and characters in the second part are the
same.
[0627] In this embodiment, a structure will be described in which the movable
member 452 of the separation/contact mechanism of the process cartridge 400
operates in the developing unit 109 without moving from the accommodated
position to the projecting position. The movable member does not move from
the accommodated position to the projecting position, but performs the same
action by moving the developing unit 109 or the process cartridge 400 up and
down. When the image forming apparatus main assembly 170 is installed on a
horizontal surface, the vertical directions are the Z1 direction and the Z2 direction.
[Structure of process cartridge 400]
[0628] The process cartridge 400 includes a separation/contact mechanism
450R on the drive-side and a separation/contact mechanism 450L on the non- drive-side. Regarding the separation/contact mechanism, the details of the separation/contact mechanism 450R on the drive-side will first be described, and then the separation/contact mechanism 450L on the non-drive-side will be described. Further, the separation/contact mechanism has almost the same function on the drive-side and the non-drive-side, and therefore, R is added to the end of the code of each member on the drive-side. For the non-drive-side, the reference numerals and characters of each member are the same as that of the drive-side, but L is added at the end.
[0629] Figure 67 is an assembly perspective view of the drive-side of the
process cartridge 400 including the separation/contact mechanism 450R. The
separation/contact mechanism 450R has a spacer 151R which is a restricting
member (holding member), a movable member 452R which is an urging member,
and a tension spring 153. The movable member 452R is provided with a
support receiving portion 452Ra which is a round through hole. Further, as
shown in Figure 69, the movable member 452R is provided with a projecting
portion 452Rh capable of projecting from the developing unit in the ZA direction,
and the projecting portion 452Rh includes a first force receiving portion
(retracting force receiving portion, separating force receiving portion) 452Rk, and
a second force receiving portion (contact force receiving portion) 452Rn. The
movable member 452R is swingably mounted to the second retaining portion
428m of the development cover member 428.
[0630] The development supporting member 401R is mounted to the end
surface of the development cover member 428. The developing supporting
member 401R is provided with a supporting cylinder 41ORa, a supporting spring
receiving portion 401b, and a positioning receiving portion 401Rc. The
development supporting member 401R is mounted so that the inner surface of the
supporting cylinder 401Ra is fitted with the cylindrical portion 428b of the development cover member 428. Further, the outer surface of the supporting cylinder 401Ra is supported movably in the ZA direction by the developing unit supporting hole 416a of the drive-side cartridge cover member 416 forming a portion of the drum frame of the drum unit 408. Further, the development supporting member 401R is provided with a slide guide 40IRe. Theslideguide
401Re is positioned in the proper attitude by engaging with the guide projection
416e provided on the drive-side cartridge cover member 416 and restricting the
movement so as to be movable in the groove direction. The slide guide 40IRe
in the form of a groove parallel to the ZA direction in which the developing unit
409, which will be described hereinafter, moves up and down. The support
method will be described hereinafter.
[0631] One end of the development supporting spring 402 is mounted to the
drive-side cartridge cover member 416. The other end side of the development
supporting spring 402 is placed at a position in contact with the supporting spring
receiving portion 401Rb of the assembled development supporting member 401R.
By this, the development supporting spring 402 applies a force to the drive-side
cartridge cover member 416 to lift the development supporting member 401R in
the direction opposite to the ZA direction.
[0632] Figure 68 shows an assembly perspective view of the non-drive-side of
the process cartridge including the separation/contact mechanism 450L. The
assembled state of the separation/contact mechanism 450L will be described.
[0633] The non-drive-side bearing member 427 is fixed to the developing
frame 125 and rotatably supports the developing roller 106 and the toner feeding
roller 107. The non-drive-side bearing member 427 includes a support
cylindrical portion 427a for supporting the development supporting member
401L, a support portion 427b for supporting the spacer 151L, and a support
portion 427f for supporting the movable member 452L. Further, as shown in
Figure 70, the movable member 452R includes a projecting portion 452Lh
capable of projecting from the developing unit in the ZA direction, and the
projecting portion 452Rh includes a first force receiving portion (retracting force
receiving portion, separating force receiving portion) 452 Lk, a second force
receiving portion (contact force receiving portion) 452Ln is provided.
[0634] The development supporting member 401L is supported by fitting the
oblong round hole 401Lb into the support cylindrical portion 427a of the non
drive-side bearing member 427. This oblong round hole is provided in the
support portion 401Lb on the non-drive-side in order to allow a deviation due to a
manufacturing error between the drive-side and the non-drive-side of the portion
supporting the developing unit 409.
[0635] The development supporting member 401L is provided with a
cylindrical portion 401La so as to cover the oblong round hole 401Lb. The
cylindrical portion 401La is supported by the developing unit supporting hole
417a of the non-drive-side cartridge cover member 417.
[0636] Further, the development supporting member 401L is provided with a
guide projection 401Le. The guide projection 401Le is fitted with the groove
shaped slide guide 417e provided on the non-drive-side cartridge cover member
417, and the movement is restricted so as to be movable in the longitudinal
direction (ZA direction) of the groove, so as to be positioned in the proper
attitude. The slide guide 417e includes a groove parallel to the ZA direction in
which the developing unit 409, which will be described hereinafter, moves up and
down. The support method will be described hereinafter.
[0637] The development supporting member 401L obtains a force by the
development supporting spring to lift the cartridge cover member 417 on the non
drive-side in the direction of arrow Z1 which is upward.
[0638] Figure 69 is side view of the process cartridge 400 as viewed from the drive-side, and Figure 70 shows a side view of the process cartridge 400 as viewed from the non-drive-side.
[0639] Referring to Figure 69, the mechanism on the drive-side in the
assemblage completed state will be described.
[0640] In the developing unit 409, the supporting cylinder 401Ra of the
development supporting member 401R is supported by the developing unit
supporting hole 416a of the drive-side cartridge cover member 416. The
developing unit supporting hole 416a is an oblong round hole oblong in the
direction of arrow ZA. By this, the development supporting member 401R can
move in the developing unit supporting hole 416a in the ZA direction and the
opposite direction. The development supporting spring 402 is shown by a
broken line as a perspective view. The development supporting spring 402
pushes up the supporting spring receiving portion 401b of the development
supporting member 401R in the direction opposite to the ZA direction. Since
the development supporting member 401R supporting the developing unit 409 is
pushed up in the direction opposite to the ZA direction, the developing unit 409 is
lifted in the drive-side cartridge cover member 416 in the direction opposite to
the ZA direction.
[0641] In this Figure, the photosensitive member drum and the developing
roller are spaced from each other in the state that the process cartridge 400 is
outside the apparatus main assembly 170. Similar to the other embodiments, the
spacer 151R contacts with the contact surface 416c of the drive-side cartridge
cover member 416 to prevent the developing unit 109 from approaching to the
photosensitive member drum.
[0642] Referring to Figure 70, the mechanism on the non-drive-side in the
assemblage completed state will be described. A supporting cylinder 401La of
the development supporting member 401L is supported by the developing unit supporting hole 417a of the non-drive-side cartridge cover member 417. The developing unit supporting hole 417a movably supports the supporting cylinder
402La by two surfaces 417al and 417a2 parallel to the ZA direction which is the
same direction in which the oblong round hole the supporting hole 416a on the
drive-side extends. Further, the movement amount of the development
supporting member 401L is restricted by the lower restriction surface 417a3.
The non-drive-side cartridge cover member 417 movably supports the developing
supporting member 41OL in the ZA direction and the opposite direction by the
developing unit supporting hole 417a.
[0643] The development supporting spring 402L is pushed up the supporting
spring receiving portion 401Lb of the development supporting member 401L in
the direction opposite to ZA direction. Since the development supporting
member 401L supporting the developing unit 409 is pushed up in the opposite
direction in the ZA direction, the developing unit 409 is lifted in the non-drive
side cartridge cover member 417 in the direction opposite to the ZA direction.
[Operation when process cartridge is mounted to main assembly of apparatus]
[0644] Next, referring to Figure 71, the operation when the process cartridge
400 is mounted on the apparatus main assembly will be described. Figure 71 is
a side view of the process cartridge 400 and the portions of the apparatus main
assembly 170 related to mounting as viewed from the drive-side. Part (a) of
Figure 71 shows the process cartridge 400 which is being mounted while moving
in the direction of the arrow X1 between the pressing mechanism 191 of the
apparatus main assembly 170 on the upper side and the development separation
control unit 195 on the lower side. The operation mechanism of the pressing
mechanism 191 (the mechanism that moves in the Z1 and Z2 directions in
interrelation with the opening and closing of the front door 11) is the same as that
of the Embodiment 1, and therefore, detailed description thereof will be omitted.
The movable member 452R is in a state of having been advanced to the front of
the separation control member 196R. The process cartridge 400 moves while
kept carried on the tray 171 shown in Figure 5, but for simplification of the
drawing, the entire tray 171 is not illustrated, and only the portion supporting the
drive-side cartridge cover member 416 is shown by broken lines.
[0645] Part (b) of Figure 71 shows a state in which the process cartridge 400
advances in the X1 direction and the movable member 452R is above the
separation control member 196. In the steps from part (a) of Figure 71 to part
(b) of Figure 71, the movable member 452R has been lifted together with the
developing unit in the direction of arrow Z Iand is in the accommodated position
(stand-by position), so that it does not interfere with the separation control
member 196R.
[0646] Part (c) of Figure 71 shows a state in which the process cartridge 400
has advanced to the mounting position relative to the image forming apparatus
main assembly 170 in the X1 direction. It shows the state in which the pressing
mechanism 191 starts to push the pressed portion 401Rc of the developing
supporting member 401 in the direction of arrow Z2. When the development
supporting member 401 is pushed in at least the Z2 direction by the pressing
mechanism 191, the entire developing unit 409 moves in the ZA direction
(predetermined direction), and the movable member 452R also moves in the ZA
direction (predetermined direction) to the projecting position (operating position)
inside the space 196Rd of the separation control member 196. At this time, the
development supporting spring 402 having been described referring to Figure 69
is compressed by the force from the pressing mechanism 191. Then,the
developing supporting member 401 moves in the ZA direction along the oblong
round hole of the developing unit supporting hole 416a. The ZA direction is a
direction perpendicular to the X1 direction.
[0647] Part (d) of Figure 71 shows a state after the pressing mechanism 191 is
further moved from the state of part (c) of Figure 71 in the direction of arrow Z2.
The pressing mechanism 191 presses the positioning receiving portion 410Rc of
the developing supporting member 401 in the direction of arrow Z2 and pushes it
down. By this, the entire developing unit 409 is pushed down in the direction of
arrow ZA, and the movable member 452R enters the space 196Rd of the
separation control member 196. In this state, the mounting of the process
cartridge 400 to the apparatus main assembly 170 is completed.
[0648] At this time, the spring force of the developing supporting spring 402
in the direction opposite to the ZA direction is set to be lower than the pressing
force of the pressing mechanism 191. Further, it is desirable that the developing
supporting spring 402 is placed so as to expand and contract in the ZA direction,
but if the spring force is selected appropriately, it may be placed so as to expand
and contract in another direction including the ZA direction component.
[0649] The operation when the process cartridge 400 is removed from the
apparatus main assembly 170 is the reverse of the above-mentioned operation
when the process cartridge 400 is mounted, and therefore, the description thereof
will be omitted.
[Contact operation and separation operation of developing unit]
[0650] Referring to Figure 72, the operation in which the developing unit 109
of the mounted process cartridge 400 contacts and separates from the
photosensitive member drum will be described.
[0651] Figure 72 is a side view seen from the drive-side, and the pressing
mechanism 191 shown in Figure 71 is not shown.
[0652] Part (a) of Figure 72 is an illustration of an operation for bringing the
developing unit 109 into contact with the photosensitive member drum. When
the separation control member 196R moves in the arrow W42 direction, the movable member 452R is pushed and moves. At this time, the movable member 452R swings in the direction of arrow BC about the support receiving portion 452Ra which is around hole. The spacer 151R is pushed by the movable member 452R and swings in the direction of arrow B2. The spacer
151R moves from the contact surface 416c and enters the second restriction
surface 416d to disable the distance restriction between the photosensitive
member drum and the developing unit 109 to bring the developing unit 409 into
contact state.
[0653] Part (b) of Figure 72 is an illustration in which the developing unit 109
is maintained in contact with the photosensitive member drum. The separation
control member 196R which has moved in the W42 direction in part (a) of Figure
72 returns to the W41 direction again. Since the space 196Rd is wide enough
such that the separation control member 196R and the movable member 452R do
not come into contact with each other. The movable member 452R maintains
the above-described contact state.
[0654] Part (c) of Figure 72 is an illustration of an operation when the
developing unit 109 is separated again. When the separation control member
196R further moves in the direction of W41 from the state of part (b) of Figure 72,
the separation control member 196R and the movable member 452R is brought
into contact with each other. Then, the movable member 452R swings in the
direction of the arrow BD and comes into contact with the development cover
member 428. When the movable member 452R comes into contact with the
development cover member and then is further rotated in the BD direction, the
developing unit 109 swings to establish the spaced state. At this time, the
movable member 452R and the spacer 151R are connected by a tension spring
153 and rotate in the direction of arrow Bl. The rotated spacer 151R contacts to
the contact surface 416c to restrict the developing unit 109 in the spaced state.
Thereafter, when the separation control member 196R moves in the direction of
W42 and returns to the position shown in part (d) of Figure 71, the developing
unit 109 maintains the spaced state without receiving the force of the separation
control member 196R.
[0655] According to the structure of this embodiment described above, the
same effect as that of an Embodiment 1 can be obtained.
[0656] Further, in this embodiment, the movable member 425 including the
first force receiving portions 452Rk and 452Lk and the second force receiving
portions 452Rn and 452Ln moves integrally with the developing unit 409
between the accommodated position (stand-by position) and the projecting
position (operating position). By this movement, the first force receiving
portions 452Rk and 452Lk are displaced at least in the directions VD1 (Figure 40,
and so on), the direction VD10 (Figure 236, and so on), the direction VD12
(Figure 238), and the direction VD14 (Figure 239). With such a structure, it is
possible to prevent the movable member 42 from interfering with the apparatus
main assembly 170, particularly the separation control member 196L, when the
process cartridge 400 is inserted into or removed from the apparatus main
assembly 170.
<Another example of Embodiment 5>
[0657] Using another structure shown in Figure 73 to Figure 78, the
description will be made as to the example in which in the separation/contact
mechanism of the process cartridge 430, the movable member, which is a
pressing member, operates in the developing unit 109 without moving from the
accommodated position (stand-by position) to the projecting position (operating
position). The structure.
[0658] In the structure described here, when the process cartridge is mounted
on the apparatus main assembly 170, the process cartridge 430 retracts in a direction perpendicular to the mounting direction and finally engages with the separation control member 196.
[0659] Referring to Figure 73, a characteristic structure will be described.
Part (a) of Figure 73 shows a side view of the process cartridge 430 in this
structure, as viewed from the drive-side. The support structure for the
developing unit 439 is the same as that described with Embodiment 1. That is,
the cylindrical portion 428b of the development cover member 428 is rotatably
supported by the developing unit supporting hole 431Ra of the drive-side
cartridge cover member 431R. Here, the developing unit supporting hole 431Ra
has a cylindrical shape. Therefore, in the present alternative example, unlike the
structure of the Embodiment 5, the developing unit 439 is unable to move in the
Z2 direction relative to the drive-side cartridge cover member (drum frame) 431R
and the drum unit 438, except for the movement due to play.
[0660] Compression coil springs (elastic members) are mounted to the drive
side cartridge cover member 431R at two locations. One of themis the first
drive-side supporting spring 435R provided in the rotational direction position
setting recess 431KR of the drive-side cartridge cover member 431R. The
spring 435R has a free end portion 435Ra on the lower end side thereof. The
other of them is a second drive-side supporting spring 434R mounted to the
drive-side supporting spring attachment portion 431MR. The spring 434Rhas a
free end portion 434Ra on the lower end side thereof.
[0661] Part (b) of Figure 73 shows a side view of the process cartridge 430 as
viewed from the non-drive-side. The cartridge cover member 431L on the non
drive-side rotatably supports the developing unit 409 as in Figure 13 of the
Embodiment 1. Compression coil springs (elastic members) are mounted to a
non-drive-side cartridge cover member 431L at two locations. Oneofthemisa
first non-drive-side supporting spring 435L provided in the rotational direction position setting recess 431KL of the non-drive-side cartridge cover member 431L.
The spring 435L has a free end portion 435La on the lower end side thereof.
The other of them is a second non-drive-side supporting spring 434L mounted to
the non-drive-side supporting spring mounting portion 431ML. Thespring
434L has a free end portion 434La on the lower end side thereof.
[0662] These free end portions 434Ra, 435Ra, 434La, and 435La are
supported portions which are supported in contact with the tray 171. Further,
these free end portions 434Ra, 435Ra, 434La, and 435La are also supporting
portions to support, so as to be movable in the Z2 direction, the drive-side
cartridge cover member 431R and the non-drive-side cartridge cover member
431L which forma portion of the drum frame (first frame). Here,the
developing unit 409 (or developing frame) (second frame) is supported by the
drum frame. Therefore, it can be said that these free end portions 434Ra, 435Ra,
434La, and 435La support the developing unit 409 (or the developing frame)
movably in the Z2 direction by way of the drum frame.
[0663] Next, referring to Figure 74, the relative positions of the first drive-side
supporting spring 435R and the second drive-side supporting spring 434R and the
tray 171 when the process cartridge 430 is mounted on the tray 171 will be
described. Figure 74 shows the process cartridge 430 which is being moved in
the direction of arrow Z2 in order to be mounted on the tray 171. In this state,
the process cartridge 430 is still movable in the Z2 direction and is not positioned
on the tray 171.
[0664] When the process cartridge 430 is further advanced in the Z2 direction,
the first drive-side supporting spring 435R provided on the drive-side cartridge
cover member 431R is brought into contact with and supported by the rotational
direction position setting projection (first spring support portion) 171KR of the
rotation of the tray 171 at the free end portion 435Ra thereof. Further, when the process cartridge is advanced in the Z2 direction, the free end portion 434Ra of the second drive-side supporting spring 434R brought into contact with and supported by the spring receiving portion (second spring support portion) 471MR of the tray 171.
[0665] On the other hand, also on the non-drive-side, the free end portion
435La of the first non-drive-side supporting spring 435L is brought into contact
with and supported by the rotational direction position setting projection (third
spring supporting portion) of the tray 17. Further, the free end portion 434La of
the second non-drive-side supporting spring 434L is brought into contact with to
and is supported by a spring receiving portion (fourth spring supporting portion)
(not shown) of the tray 17.
[Operation upon mounting of process cartridge to apparatus main assembly]
[0666] Next, referring to Figures 75 to 78, a process from the state in which
the process cartridge 430 is placed on the tray 171 to the state in which it is
positioned in the image forming apparatus main assembly 170 at the position
where the image is formed will be described. Figure 75 to Figure 78 show side
views as viewed from the drive-side. In these Figures, for the sake of simplicity,
all but the relevant structures are not shown to illustrate the states. Since the
non-drive-side has the same structure as the drive-side and operates in the same
manner, the description thereof will be omitted.
[0667] Figure 75 shows a state in which the process cartridge 430 placed on
the tray 171 advances in the direction of arrow X1 together with the tray 171.
As described referring to Figure 74, the free end portion 435Ra of the first drive
side supporting spring 435R is in contact with the rotational direction position
setting projection 171KR of the tray 171. Further, the free end portion 434Ra of
the second drive-side supporting spring 434R is in contact with the spring
receiving portion 471MR of the tray 171.
[0668] The first drive-side supporting spring 435R and the second drive-side
supporting spring 434R are supported by the tray 171 to support the drum frame
and the developing frame portion of the process cartridge 430 against the gravity.
By this, the arc 431VR, which is a positioned portion provided on the drive-side
cartridge cover member 431R of the process cartridge 430, is not in contact with
the straight portions 171VR1 and 171VR2 which are the positioning portions of
the tray 171, with the gap G4 maintained. That is, the process cartridge 430 is
supported in the Z Idirection with respect to the positioning portion of the tray
171 by the first drive-side supporting spring 435R and the second drive-side
supporting spring 434R. Therefore, when the process cartridge 430 moves to
the arrow X1 by the tray 171 being inserted into the apparatus main assembly 170,
the movable member 452R can pass through without colliding with the separation
control member 196R. It can be said that the movable member 452R is in the
accommodated position (stand-by position). At this time, the cartridge pressing
mechanism 191 is in a state of standing by with the gap G5 relative to a top
surface 431Rc of the drive-side cartridge cover member 431R.
[0669] Figure 76 shows a state in which the cartridge pressing mechanism 191
moves in the direction of arrow Z2 in interrelation with closing the front door 11
and contacts the top surface 431Rc of the drive-side cartridge cover member
431R. The first drive-side supporting spring 435R and the second drive-side
supporting spring 434R have not yet received a force from the cartridge pressing
mechanism 191, and the process cartridge 430 has not yet moved. Figure77
shows a state in which the cartridge pressing mechanism 191 further moves in the
direction of arrow Z2 and starts pushing the top surface 431Rc of the drive-side
cartridge cover member 431R in the Z2 direction. The process cartridge 430
moves in the ZA direction, and the first drive-side supporting spring 435R and
the second drive-side supporting spring 434R are compressed. The arc 431VR, which is the positioning portion of the process cartridge 430 with the tray 171, approaches, but does not come into contact with the straight portions 171VR1 and 171VR2 of the tray, with the gap G6 maintained. The movable member
452R enters the space 196Rd of the separation control member 196R because the
process cartridge 430 moves in the ZA direction.
[0670] Figure 78 shows a state in which the cartridge pressing mechanism 191
is further moved in the direction of arrow Z2, and the process cartridge 430 is
positioned on the tray 171.
[0671] By the movement of the cartridge pressing mechanism 191 in the Z2
direction, the process cartridge is moved in the ZA direction, and finally the arc
431VR comes into contact with the straight portions 171VR1 and 171VR2 of the
tray 171. By this, the position of the process cartridge 430 is determined
relative to relative to the tray 171 in the Z2 direction. The movable member
452R is inserted into the space 196Rd of the separation control member 196R to
the final position by the movement of the process cartridge 430 in the Z2
direction. At this time, it can be said that the movable member 425R is in the
projecting position (operating position). Therefore, by the movement of the
separation control member 196R, the movable member 452R can be moved to
switch between the contact state and the separation state of the process cartridge
430.
[0672] The ZA direction (the direction in which the movable member 425R
moves from the stand-by position to the operating position) in which the process
cartridge 430 is moved by being pressed by the cartridge pressing mechanism 191
moving in the arrow Z2 direction does not have to be parallel to the arrow Z2
direction. That is, it will suffice if the ZA direction includes at least a
component in the direction perpendicular to the X1 direction.
[0673] The spring force (power) of the first drive-side supporting spring 435R and the second drive-side supporting spring 434R in the state that the arc 431VR is in contact with the straight portions 171VR1 and 171VR2 is selected to be smaller than the force of the cartridge pressing mechanism 191. Therefore,the process cartridge 430 can be reliably positioned relative to the tray 171.
[0674] After the mounting is completed, the operation is the same as that
described referring to Figure 72, and therefore, the description thereof will be
omitted.
[0675] The operation when the process cartridge 430 is removed from the
apparatus main assembly is the reverse of the above-mentioned operation when
the process cartridge 430 is mounted, and thus the description thereof will be
omitted.
[0676] According to the structure of the present alternative embodiment
described above, the same effect as that of the Embodiment 1 can be provided.
[0677] Further, in this alternative example, the movable member 425
including the first force receiving portions 452Rk and 452Lk and the second
force receiving portions 452Rn and 452Ln is moved between the (stand-by
position) and the projecting position (operating position) integrally with the drum
unit 438 and the developing unit 439 (drum frame and developing frame). By
this movement, the first force receiving portions 452Rk and 452Lk and the
second force receiving portions 452Rn and 452Ln are displaced at least in the
direction VD1 (Figure 40, and so on), the direction VD10 (Figure 236, and so on),
the direction VD12 (Figure 238), and the direction VD14 (Figure 239). With
such a structure, it can be avoided that when the process cartridge 430 is inserted
or removed into the apparatus main assembly 170, the movable member 42
interferes with the apparatus main assembly 170, particularly the separation
control member 196L.
<Embodiment 6>
[0678] In this embodiment, the structures and operations different from those in the above-described embodiment will be mainly described, and description of
similar structures and operations will be omitted. Further, for the structure
corresponding to the above-described embodiment, the same reference numerals and characters are assigned, or the reference numerals in the first part is changed
while the reference numerals and characters in the second part are the same. In
this embodiment, a structure will be described in which the movable member
applies a force to the spacer in the process cartridge separation/contact
mechanism without being pressed by a part of the main assembly side.
[0679] The structure of the separation/contact mechanism, the contact operation of the developing unit, the separation operation of the developing unit, and the
mounting/dismounting of process cartridge relative to the image forming
apparatus main assembly in this embodiment will be specifically described.
Since the structures of other process cartridges are the same as those in the above described embodiment, they are omitted here.
[Structure of separation/contact mechanism]
[0680] The structure in which the photosensitive member drum 104 of the process cartridge 1400 and the developing roller 106 of the developing unit 1409
are brought into and out of contact with each other in this embodiment will be
described in detail. The process cartridge has a separation/contact mechanism
1450R on the drive-side and a separation/contact mechanism 1450L on the non
drive-side (Figure 79). Figure 80 shows an assembly perspective view of the
drive-side of the developing unit 1409 including the separation/contact
mechanism 1450R. Figure 81 shows an assembly perspective view of the
developing unit 1409 including the separation/contact mechanism 550L on the
non-drive-side. Here, the details of the separation/contact mechanism 1450R on the drive-side will be described. Since the separation/contact mechanism has almost the same functions as the drive-side and the non-drive-side, R is included in the reference sign for each member in the drive-side. For the non-drive-side, the reference sign of each member is the same as that of the drive-side, but L is included instead of R. Then, the structure and operation of the drive-side will be described as a representative, and the description of the structure and operation of the non-drive-side will be omitted.
[0681] The separation/contact mechanism 1450R has a spacer 1451R which is a restricting member (holding member), a movable member 1452R which is a
pressing member, and a tension spring 1453.
[0682] The spacer 1451R has an annular supported portion 1451Ra, a contact surface (contacted portion) 1451Rc which contacts the contact surface (contact
portion) 1416c of the cartridge cover 1416, and a spring-hooked portion 1451Rg
which engages with the tension spring 1453, and a second pressed surface
1451Re which engages with the movable member 1452R. Further,itis rotatably supported by the first supporting portion 1428c of the development
cover member 1428. Other structures are the same as those of an Embodiment 1
described above.
[0683] The movable member 1452R is rotatably held by engaging the support receiving portion 1452Ra of the movable member 1452R with the third support
portion 1428m of the development cover member 1428. Further, the movable
member 1452R has a first force receiving surface 1452Rm and a second force
receiving surface 1452Rp which can be engaged with the separation control
member 196R provided in the apparatus main assembly 170, the spring-hooked
portion 1452Rs which engages with the tension spring 1453, and a second
pressing surface 1452Rr that engages the spacer 1451R. The first force
receiving surface 1452Rm and the second force receiving surface 1452Rp constitute the first force receiving portion (retracting force receiving portion, separating force receiving portion), and the second force receiving portion (force applying part) as in the Embodiment 1.
[0684] Further, as shown in Figure 82, the tension spring 1453 urges the
spacer 1451R in the B1 direction with the first supporting portion 1428c of the
development cover member 1428 as the center of rotation, as in an Embodiment 1
described above. Further, the movable member 1452R is urged in the CA
direction with the third support portion 1428m of the development cover member
1428 as the center of rotation.
[Contact operation of developing unit]
[0685] Next, referring to Figure 82 to Figure 85, the contacting operation
between the photosensitive member drum 104 and the developing roller 106 by
the separation/contact mechanism 1450R will be described in detail. For better
illustration, these Figures are cross-sectional views in which the development
cover member 1428 is partially omitted.
[0686] With the structure of this embodiment, a development input coupling
132 receives a driving force from the image forming apparatus main assembly
170 in the direction of arrow V2 in Figure 82 to rotate the developing roller 106.
That is, the developing unit 1409 including the development input coupling 132
receives the torque in the arrow V2 direction from the image forming apparatus
main assembly 170. As shown in Figure 82, in the case that the developing unit
1409 is in the separated position and the spacer 1451R is in the separation
holding position (restriction position, first position), even if the developing unit
1409 receives this torque and the urging force of the development pressure spring
134 which will be described hereinafter, the contact surface 1451Rc of the spacer
1451R contacts the contacted surface 1416c of the drive-side cartridge cover
member 1416, so that the attitude of the developing unit 1409 is maintained at a separated position.
[0687] Similar to the Embodiment 1 described above, in this embodiment, the
image forming apparatus main assembly 170 has a separation control member
196R corresponding to each process cartridge 1400 as described above. The
separation control member 196R is provided with a first force application surface
196Ra and a second force application surface 196Rb which project toward the
process cartridge 1400 and face each other through the space 196Rd. The first
force application surface 196Ra and the second force application surface 196Rb
are connected with each other by way of the connecting portion 196Rc on the
lower surface side of the image forming apparatus main assembly 170. Further,
the separation control member 196R is rotatably supported by a control sheet
metal (not shown) around the rotation center 196Re. The separation control
member 196R is urged in the El direction by an urging spring (not shown), and
the rotational direction is restricted by a holder (not shown). Further, since the
control sheet metal (not shown) is structured to be movable in the W41 and W42
directions from the home position by a control mechanism (not shown), the
separation control member 196R is structured to be movable in the W41 and W42
directions.
[0688] When the separation control member 196R moves in the W42 direction,
the second force application surface 196Ra of the separation control member
196R and the second force receiving surface 1452Rp of the movable member
1452R come into contact with each other, so that the movable member 1452R
rotates in the CB direction with the support receiving portion 1452Ra as the
center of rotation. Further, as the movable member 1452R rotates, the spacer
1451R is rotated in the B2 direction while the second pressing surface 1452Rr of
the movable member 1452R is in contact with the second pressed surface 1451Re
of the spacer 1451R. Then, the spacer 1451R is rotated by the movable member
1452R to the separation release position (permission position, second position)
where the contact surface 1451Rc and the contacted surface 1416c are separated,
and becomes in the state shown in Figure 83. Here, the position of the
separation control member 196R for moving the spacer 1451R to the separation
release position shown in Figure 83 is referred to as a first position.
[0689] When the spacer 1451R is moved to the separation release position by
the separation control member 196R in this manner, the developing unit 1409 is
rotated in the V2 direction by the torque received from the image forming
apparatus main assembly 170 and the development pressure spring 134, to move
to the contact position where the developing roller 106 and the photosensitive
member drum 104 are in contact with each other(state in Figure 83). At this
time, the spacer 1451R urged in the direction of arrow B1 by the tension spring
1453 is maintained at the separation release position by the second restricted
surface 1451Rk contacting the second restriction surface 1416d of the drive-side
cartridge cover member 1416. Thereafter, the separation control member 196R
moves in the direction of W41 and returns to the home position. At this time,
the movable member 1452R is rotated in the CB direction by the tension spring
1453, and as shown in Figure 84, the first pressing surface 1452Rq of the
movable member 1452R and the first pressing surface 1428k of the development
cover member 1428 become in contact with each other (See also Figure 80).
[0690] By this, gaps T3 and T4 are provided, and the distance control member
196R is placed at a position where the movable member 1452R does not act.
The transition from the state of Figure 83 to the state of Figure 84 is effected
without a delay.
[0691] As described above, in the structure of this embodiment, by moving the
separation control member 196R from the home position to the first position, the
movable member 1452R can be rotated and the spacer 1451R can be moved from the separation holding position to the separation release position. This makes it possible for the developing unit 1409 to move from the separated position to the contacting position where the developing roller 106 and the photosensitive member drum 104 contact with each other. The position of the separation control member 196R in Figure 84 is the same as that in Figure 82.
[Separation operation of developing unit]
[0692] Next, referring to Figures 84 and 85, the operation of moving the
developing unit 1409 from the contact position to the separated position by the
separation/contact mechanism 1450R will be described in detail. For better
illustration, these Figures are cross-sectional views in which a part of the
development cover member 1428 is partially omitted.
[0693] The separation control member 196R in this embodiment is structured
to be movable from the home position in the direction of arrow W41 in Figure 84.
When the separation control member 196R moves in the W41 direction, the first
force application surface 196Rb and the first force receiving surface 1452Rm of
the movable member 1452R come into contact with each other, so that the
movable member 1452R rotates in the CA direction with the support receiving
portion 1452Ra as the rotation center. Then, by the contacting of the first
pressing surface 1452Rq of the movable member 1452R to the a first pressing
surface 1428k of the development cover member 1428, the developing unit 1409
rotates in the VI direction from the contact position (state in Figure 85).
[0694] In the spacer 1451R, the second restricted surface 1451Rk of the spacer
1451R and the second restriction surface 1416d of the drive-side cartridge cover
member 1416 are separated from each other, and the spacer 1451R is rotated in
the arrow B Idirection by the urging force of the tension spring 1453. By this,
the spacer 1451R rotates until the second pressed surface 1451Re comes into
contact with the second pressing surface 1452Rr of the movable member 1452R, and by the contact, the separation holding position is reached. When the developing unit 1409 is moved from the contact position to the separation position by the separation control member 196R and the spacer 1451R is located at the separation holding position, the gap T5 is formed between the contact surface 1451Rc and the contacted surface 1416c as shown in Figure 85. Here, the position shown in Figure 85 in which the developing unit 1409 is rotated from the contact position toward the separation position and the spacer 1451R can move to the separation holding position is referred to as a second position of the separation control member 196R.
[0695] Thereafter, when the separation control member 196R moves in the
W42 direction and returns from the second position to the home position, the
developing unit 1409 rotates in the direction of arrow V2, and the contact surface
1451Rc and the contacted surface 1416c come into contact with each other by the
torque received from the image forming apparatus main assembly 170 and the
development pressure spring 134, while maintaining the separation holding
position of the spacer 1451R. That is, the developing unit 1409 becomes in a
state that the separated position is maintained by the spacer 1451R, and the
developing roller 106 and the photosensitive member drum 104 are spaced from
each other (states in Figures 82 and 79). By this, gaps T3 and T4 are formed,
and it is placed at the positions where the separation control member 196R does
not act on the movable member 1452R (state in Figure 82). The transition from
the state of Figure 85 to the state of Figure 82 is executed without a delay.
[0696] As described above, in this embodiment, the spacer 1451R moves from
the separation release position to the separation holding position by movement of
the separation control member 196R from the home position to the second
position. Then, the separation control member 196R returns from the second
position to the home position, the developing unit 1409 becomes in a state of maintaining the separation position by the spacer 145IR.
[Mounting/dismounting of process cartridge relative to image forming apparatus
main assembly]
[0697] Next, referring to Figures 86 to 101, the description will be made as to
the engagement operation of the separation/contact mechanism 1450R of the
process cartridge 1400 and the development separation control unit 196R of the
image forming apparatus main assembly 170 when the process cartridge 1400 is
mounted to and dismounted from the image forming apparatus main assembly
170. For the sake of explanation, these Figures are cross-sectional views in
which the development cover member 1428 is partially omitted.
[0698] Figure 86 to Figure 89 are illustrations of the process cartridge 1400 in
the process of inserting the cartridge tray 171 from the outside of the image
forming apparatus main assembly 170 to the image forming position from the
drive-side. Further, the parts except for the process cartridge 1400 and the
separation control member 196R are omitted. Figure 94 to Figure 97 are
illustrations of the process cartridge 1400 as viewed from the non-drive-side at
the same time points as those in Figures 86 to 89.
[0699] Figures 90 to 92 are illustrations after the tray 171 is inserted until the
process cartridge 1400 is separated and kept separated by the initial operation of
the image forming apparatus described later. Figure 93 is a view seen from the
drive-side of the process cartridge 1400, omitting all but the process cartridge
1400 and the separation control member 196R in the process of pulling out the
cartridge tray 171 from the image forming position to the outside of the image
forming apparatus main assembly 170. Figures 98 to 101 are the views of the
process cartridge 1400 as viewed from the non-drive-side at the same time point
as that of in Figures 90 to 92.
[0700] Since the image forming apparatus main assembly 170 is equipped with a plurality of process cartridges 1400 to form an image, the corresponding numbers of the separation control members 196R are provided. Therefore, in this embodiment, for convenience, the separation control members 196R (196L) are distinguished by adding a numeral to the end of the separation control member 196R (196L).
[0701] When the process cartridge 1400 carried on the tray 171 (not shown) as
shown in Figure 86 is inserted in the direction of X2, which is the internal
direction of the image forming apparatus main assembly 170, the second force
receiving surface 1452Rp of the movable member 1452R comes into contact with
the upstream side surface 196R-1p of a separation control member 196R-1 in the
inserting direction. When the tray 171 is further inserted, as shown in Figure 87,
the cartridge insertion operation is performed while the second force receiving
surface 1452Rp of the movable member 1452R is in contact with the upstream
side surface 196R-1q of the separation control member in the inserting direction.
Here, the force due to the tension spring 1453 is set to be weaker than the force
due to the urging spring (not shown) that urges the separation control member
196R in the El direction, and when the movable member 1452R and the
separation control member 196R come into contact with each other, the movable
member 1452R rotates to escape. Further, the movable member 1452R and the
spacer 1451R are structured to rotate in the B2 direction (the direction from the
separation holding position to the separation release position) and the CB
direction, which is larger than that in the state shown in Figure 83.
[0702] Therefore, the second force receiving surface 1452Rp of the movable
member 1452R rides on the upper surface 196R-1q of the separation control
member 196R-1. Therefore, the movable member 1452R moves from the
separation holding position to the separation release position, and the process
cartridge 1400 shifts from the separated state to the contact state.
[0703] When the tray 171 (not shown) is further inserted from this state, it
comes into contact with the separation control member 196R-2 adjacent to the
separation control member 196R-1 as shown in Figure 88. Similarly to the
separation control member 196R-1, the separation control member 196R-2 is
inserted while being in contact with the upstream side surface 196R-1p and the
upper surface 196R-2q in the inserting direction. At this time, the process
cartridge 1400 is still in the contact state. The process cartridge 1400 is
maintained in contact even after passing through the separation control member
196R-1. When it comes into contact with the upper surface 196R-2q, the
movable member 1452R and the spacer 1451R rotate in the B2 direction (the
direction from the separation holding position to the separation release position)
and the CB direction more than before the contact with the upper surface, and
therefore, it passes by 196R-2q. Therefore, after passing through the upper
surface 196R-2q, the movable member 1452R and the spacer 1451R rotate
slightly in the B1 direction and the CA direction while maintaining the contact
state of the process cartridge 1400. The same applies when passing through the
other two separation control members 196R-3 and 196R-4.
[0704] Figure 89 is an illustration in which the tray 171 (not shown) is
inserted to a position where an image can be formed. In this state, the second
force receiving surface 1452Rp of the movable member 1452R rides on the upper
surface 196R-2s of the separation control member 196R.
[0705] With this state, the process cartridge 1400 cannot effect the contact
operation and separation operation. However, the image forming apparatus
main assembly 170 executes an initial operation after closing the front door and
before performing image forming (printing on a recording material such as paper).
In this initial operation, the separation control member 196R performs the above
mentioned contact operation and separation operation (operations in the W41 and
W42 directions). At that time, by entering the contact operation (operation in
the W42 direction) as shown in Figure 90, the second force receiving surface
1452Rp of the movable member 1452R and the first force application surface
196Ra of the separation control member 196R come into contact with each other.
Next, by performing the separation operation (operation in the W41 direction), as
shown in Figure 91, the second force application surface 196Rb of the separation
control member 196R comes into contact with the first force receiving surface
1452Rm of the movable member 1452R, so that the process cartridge 1400
rotates in the direction indicated by V Iuntil the spacer 1451R comes into contact
with the movable member 1452R. When the separation control member 196R
returns to the home position in this state, the process cartridge 1400 can be
separated and kept separated as shown in Figure 82, and the same image process
operation as in the above-described embodiment is enabled.
[0706] Next, the description will be made as to the behavior of the process
cartridge 1400 when the tray 171 (not shown) is pulled out from the image
forming position to the outside of the image forming apparatus main assembly
170. When the process cartridge 1400 is pulled out in the direction X1 which is
an outward direction of the image forming apparatus main assembly 170 as
shown in Figure 93, the first force receiving surface 1452Rm of the movable
member 1452R contacts the separation control member 196R, and the surface
1452Rq of the movable member 1452R contact with the first pressing surface
1428k of the development cover member 1428, so that the developing unit 1409
rotates in the VI direction. When the tray 171 is pulled out, it is further rotated
in the VI direction from the separated state shown in Figure 85, and the state
shown in Figure 93 results. That is, the developing unit is structured such that
the developing roller 106 is more remote away from the photosensitive member
drum 104 than in the state shown in Figure 85. At this time, the process cartridge 1400 is pulled out while the first force receiving surface 1452Rm of the movable member 1452R is in contact with the upper surface 196R-2r of the separation control member 196R. In this manner, when the process cartridge
1400 is pulled out from the image forming apparatus main assembly 170, the
developing unit 1409 is pulled out while being separated. When the tray 171
(not shown) is pulled out to the outside of the image forming apparatus main
assembly 170, the process cartridge 1400 becomes in the same state as the
separated process cartridge 1400 shown in Figure 82. In this manner, even if the
developing unit 1409 rotates in the VI direction by contacting the separation
control member 196R, the process cartridge 1400 remains in the separated state.
[0707] In the foregoing description of this embodiment, only the drive-side
has been dealt with. Since the non-drive-side has the same structure and
operation as the drive-side, the description thereof will be omitted in this
embodiment.
[0708] According to the structure of this embodiment described above, the
same effect as that of Embodiment 1 can be obtained.
[0709] Further, in this embodiment, the movable member 1452R, the first
force receiving surface 1452Rm constituting the first force receiving portion
(retracting force receiving portion, separating force receiving portion), and the
second force receiving surface 1452R Page constituting the second force
receiving portion (contact force receiving portion) are made movable relative to
the drum unit. In this embodiment, by this movement, the first force receiving
surface 1452Rm and the second force receiving surface 1452Rp displaced at least
the direction VD1 (Figure 40, and so on), the direction VD10 (Figure 236, and so
on), the direction VD12 (Figure 238), and the direction VD14 (Figure 238). In
particular, when the tray 171 is inserted into the image forming apparatus main
assembly 170, the process cartridge 1400 is inserted, and the process cartridge
1400 is passed by the upper surface 196R-q of the separation control member
196R, the first force receiving surface 1452Rm and the second force receiving
surface 1452Rp can be displaced in these directions, while maintaining the
contact state of the developing unit. Further, when the tray is drawn out from
the image forming apparatus main assembly 170 and the process cartridge 1400 is
drawn out, the first force receiving surface 1452Rm and the second force
receiving surface 1452Rp can be displaced in these directions while maintaining
the separated state of the developing unit.
[0710] By this, when the process cartridge 1400 is inserted into or removed
from the apparatus main assembly 170, it can be avoided that the movable
member 1452R (particularly the first force receiving surface 1452Rm and the
second force receiving surface 1452Rp) and the apparatus main assembly 170,
particularly the separation control member 196L interfere with each other with
the result of incapability of the insertion or the removal.
<Embodiment 7>
[0711] Next, referring to Figures 102 to 115, Embodiment 7 of the present
invention will be described. In this embodiment, structures and operations
different from those of the above-described embodiment will be mainly described,
and description of similar structures and operations will be omitted.
[0712] For the structure corresponding to that in the above-described
embodiments, the same reference numerals and characters are assigned, or the
reference numerals in the first part is changed while the reference numerals and
characters in the second part are the same. In this embodiment, the structure
will be described in which the movable member, which is a pressing member in
the separation/contact mechanism of the process cartridge 1600, is projected from
the accommodated position (stand-by position) to the operating position by the driving force transmitted by the drive transmission mechanism of the image forming apparatus main assembly 170.
[0713] The process cartridge 1600 includes a separation/contact mechanism 1650R on the drive-side and a separation/contact mechanism 1650L on the non
drive-side. Regarding the separation/contact mechanism, the details of the separation/contact mechanism 150R on the drive-side will first be described, and
then the separation/contact mechanism 150L on the non-drive-side will be
described. Further, since the separation/contact mechanism has almost the same
function on the drive-side and the non-drive-side, R is added to the reference
signs for the drive-side. For the non-drive-side, the reference sign of each
member is the same as that of the drive-side but L is added.
[0714] Figure 102 shows an assembly perspective view of the drive-side of the developing unit 1609 including the separation/contact mechanism 1650R. The
separation/contact mechanism 1650R includes a spacer 151R which is a
restricting member, a movable member 1652R which is a pressing member, and a tension spring 153. Further, as shown in Figures 103 and 106, the movable
member 1652R includes a first force receiving portion (retracting force receiving
portion, separating force receiving portion) 1652Rk and a second force receiving
portion (contact force receiving portion) 1652Rn, as in the Embodiment 1.
[0715] The movable member 1652R is provided with a rack portion 1652Rx, and the outer diameter of the second supporting portion 1628k of the
development cover member 1628 and the inner wall of the oblong support
receiving portion 1652Ra are engaged with each other, and the movable member
1652R is supported so as to be linearly movable and rotatable (Figure 103). The
rack portion 1652Rx engages with the gear portion 1632-15b of the movable
member drive gear 1632-15, and is structured to be movable in interrelation with
the rotation of the movable member drive gear 1632-15. The movable member drive gear 1632-15 is structured as a portion of the development drive input gear unit1632-1. In the development drive input gear unit 1632-1, the inner diameter portion of the cylindrical portion 1628b of the development cover member 1628 and the outer diameter portion of the cylindrical portion 1632-1lb of the development coupling gear 1632-11 are engaged with each other, and in addition, the supporting portion 1626a of the drive-side bearing 1626 and the cylindrical portion (not shown) of the transmission gear 1632-16 are engaged with each other, By which the driving force can be transmitted to various gears.
Further, similarly to Embodiment 1, the first supporting portion 1628c of the
development cover member 1628 is fitted with the inner diameter of a support
receiving portion 151Ra of the spacer 151R, the spacer 151R is rotatably
supported, and the movable member 1652R and the spacers 151R are urged by
the tension spring 153 to each other In addition, the outer diameter of the
cylindrical portion 1628b of the development cover member 1628 is fitted into
the developing unit supporting hole 1616a of the drive-side cartridge cover
member 1616, so that the developing unit 1609 is supported so as to be rotatable
about the swing axis K.
[0716] Next, referring to Figures 103 to 107, the contacting and separating
operations of the separation/contact mechanism on the drive-side in this
embodiment will be described in detail.
[0717] Figure 103 is a view as seen from the non-drive-side of a process
cartridge 1600, when the process cartridge 1600 is mounted on a cartridge tray
(not shown) of the image forming apparatus main assembly 170 and the cartridge
tray 1161 is inserted at the first mounting position, in which the members are
omitted except for the drive-side cartridge cover member 1616, the development
cover member 1628, and the development drive input gear unit 1632-1, the
movable member 1652R, and the spacer 151R. In this state, the movable member 1652R is in the stand-by position. From this state, the development drive coupling 185 in the main assembly side moves in interrelation with the transition from the open state to the closed state of the front door 11 of the image forming apparatus main assembly 170 to engage with the development coupling
(rotational drive force receiving portion) 1632-11, as in the Embodiment 1.
Thereafter, when the development coupling 1632-11 is rotated by the driving
force of the main assembly and the development drive input gear unit 1632-1 is
rotated in the direction of the arrow D1, the movable member drive gear 1632-15
is rotated in the direction of the arrow D1 in interrelation therewith. At this time,
the rack portion 1652Rx of the movable member 1652R meshes with the gear
portion 1632-15b of the movable member drive gear 1632-15, and therefore, it
projects downward in the arrow Z2 direction (state in Figure 104). At this time,
since the movable member 1652R is urged by the tension spring 153 substantially
parallel to the arrow ZI direction, the terminal portion 1652Ry of the rack portion
1652Rx and the gear portion 1632-15b of the movable member drive gear 1632
15 intermittently repeats the contact with each other, and by the internal
mechanism of the development drive input gear unit 1632-1 which will be which
will be described hereinafter, the movable member drive gear 1632-15 to stops
rotating and the movable member 1652R stops at the projecting position
(operating position). When this operation is completed, as shown in Figure 104,
the movable member 1652R is placed in the projected position (operating
position) between the first force application surface 196Ra and the second force
application surface 196Rb of the separation control member 196R the separation
control member 196R. At this time, as in the Embodiment 1, there is a gap
between the projecting portion 1652Rh and the first force application surface
196Ra and the second force application surface 196Rb. As described above, in
this embodiment, by the development coupling 1632-11 receiving the driving force, the movable member 1652R moves in the Z2 direction (predetermined direction) and shifts from the stand-by position to the operating position.
[0718] Next, referring to Figures 104 to 107, the operation of contact and the
operation of separation between the photosensitive member drum 104 and the
developing roller 106 by the separation/contact mechanism 1650R will be
described. However, since the subsequent operations are the same as those
described in the Embodiment 1, an operation different from that of the
Embodiment 1 will be described. The separation/contact mechanism 1650R
comprises the spacer 151R, the movable member 1652R, and the tension spring
153. As shown in Figure 105, by the separation control member 196R moving
from the home position to the first position, the movable member 1652R rotates
in the direction of arrow BB about the second supporting portion 1628k of the
development cover member 1628. At this time, the spacer 151R also rotates in
the direction of arrow B2 in interrelation therewith, by which the developing unit
1609 moves to the contact position. Thereafter, as shown in Figure 106, when
the separation control member 196R moves in the W41 direction and returns to
the home position, the movable member 1652R is rotated in the arrow BA
direction by the urging member (not shown) to move the position not operated by
the separation control member 196R, as in embodiment 1. As the urging
member (not shown), a tension spring 153 may be used as in the Embodiment 1.
[0719] Next, when the separation control member 196R moves in the direction
of W41 for the separation operation, the movable member 1652R further rotates
in the direction of arrow BA from the state of Figure 106, and the first pressing
surface 1652Rq of the movable member 1652R is brought into contact with the
first pressed surface 1626c of the drive-side bearing 1626, by which the
developing unit 109 rotates from the contact position to the separated position.
At this time, the rack portion 1652Rx comes into contact with and meshes with the gear portion 1632-15b of the movable member drive gear 1632-15 (state in
Figure 107). Thereafter, when the separation control member 196R moves in
the W42 direction and returns from the second position to the home position, the
separation holding surface 151Rc of the spacer 151R and the contact surface
1616c are brought into contact with each other, so that the developing roller 106
and the photosensitive member drum 104 are spaced from each other (state
shown in Figure 104).
[0720] Next, referring to part (a) of Figure 108 and part (b) of Figure 108, the
internal mechanism of the drive input gear unit 1632-1 will be described. The
drive input gear unit 1632-1 includes the development coupling gear 1632-11, a
compression spring 1632-12, a clutch plate 1632-13, a torque limiter 1632-14, a
movable member drive gear 1632-15, and a transmission gear 1632-16. Only
the movable member drive gear 1632-15 is shown as a detailed view of the gear
portion 1632-15b of the gear, and the other gears are shown with the tooth shape
omitted. In the development coupling gear 1632-11, a coupling portion
(development coupling member) 1632-11a which engages with the development
drive coupling 185 on the main assembly side and a developing roller drive gear
1632-11c which engages with the developing roller gear 131 are provided with
the cylindrical portion 1632-1lb therebetween. Further, the development
coupling gear 1632-11 is provided with a projecting portion 1632-11d projecting
from a side opposite to the side on which the coupling portion 1632-11a is
provided so as to engage with the plurality of first projections 1632-13a of the
clutch plate 1632-13 to transmit the drive. In addition, a driving shaft 1632-11e
for transmitting the drive force to the transmission gear 1632-16 is provided
extended in the same direction as the projecting portion 1632- 11d, and a storage
space 1632-11f is formed in the developing roller gear 1632-11c and the
cylindrical portion 1632-1lb. The clutch plate 1632-13 is provided with a second projecting portion 1632-13c projecting by way of a flange portion 1632
13b on the side opposite to the side on which a first projecting portion 1632-11a
is provided, and is engageable with the recess 1632-14a of the torque limiter.
The torque limiter 1632-14 is provided with a projecting portion 1632-14b which
projects on the side opposite to the side on which the recess 1632-14a is provided
so as to be engageable with the recess 1632-15a of the movable member drive
gear 1632-15. The clutch plate 1632-13 and the torque limiter 1632-14 are
structured to always rotate integrally. That is, they may be integrally molded.
The transmission gear 1632-16 is provided with a recess 1632-16a which engages
with a driving shaft 1632-11e extending from the development coupling gear
1632-11, and is structured to rotate always in interrelated with the development
coupling gear 1632-11. Further, a transfer roller drive gear 1632-16b which
engages with the toner feeding roller gear 133 (see Figure 102) and a stirring
drive gear 1632-16c which engages with a stirring gear that drives a toner stirring
unit (not shown) are provided. The compression spring 1632-12 is placed in the
accommodating space 1632-1If of the development coupling gear 1632-11 and
between the clutch plate 1632-13, and urges the development coupling gear 1632
11 in the direction of arrow Y2, and urges the clutch plate 1632-13 in the
direction of arrow Y1.
[0721] Further, referring to Figure 109, a mechanism for stopping the above
mentioned movable member 1652R at the projecting position when it moves to
the projecting position will be described. Part (a) of Figure 109 is a schematic
cross-sectional view of the drive input gear unit 1632-1 when the process
cartridge 1600 is mounted on the cartridge tray 1161 and the cartridge tray 1161
is inserted in the first mounting position. When the process cartridge 1600 is
placed in the first mounting position, the projecting portion 1632-11d of the
development coupling gear 1632-11 and the first projecting portion 1632-13a of the clutch plate 1632-13 are not engaged with each other by the urging force of the compression springs 1632-12, so that the rotational driving force of the development coupling gear 1632-11 is not transmitted to the clutch plate. On the other hand, the transmission gear 1632-16 is connected to the connecting shaft 1632-11e of the development coupling gear 1632-11 at the recess 1632-16a, and the rotational driving force of the development coupling gear 1632-11 is transmitted to the transmission gear 1632-16. Thereafter, the development drive coupling 185 on the main assembly side moves in the arrow Y1 direction in interrelation with the transition of the front door I Iof the image forming apparatus main assembly 170 from the open state to the closed state. Here, because the spring force of the compression spring 1632-12 is selected to be smaller than the pressing force of the development drive coupling 185 on the main assembly side, the development drive input gear 1632-11 moves in the direction of the arrow Yl. By the development drive input gear 1632-11 moving in the direction of the arrow Y1, the projection 1632-1Id and the first projection 1632-13a of the clutch plate 1632-13 engage with each other so that rotational driving force is transmitted of the development coupling gear 1632-11 to the clutch plate 1632-13 (see part (b) of Figure 109). As the clutch plate
1632-13 rotates, the torque limiter 1632-14 connected to the clutch plate 1632-13
also rotates, and the movable member drive gear 1632-15 connected to the torque
limiter 1632-14 also rotates. As described above, by the rotation of the movable
member, the movable member drive 1652R is moved to the projecting position.
When moved to a predetermined projecting position, the movable member 1652R
receives a predetermined urging force FT by the tension spring 153 (see Figure
104). Here, the set value of the torque at which the torque limiter 1632-14 idles
without transmitting the rotational driving force is set and so on as to be
equivalent to the load torque generated by the urging force FT of the tension spring about the center of the drive input gear unit 1634-1 when the movable member 1652R is in the projecting position. By this, when the movable member 1652R receives a driving force from the movable member drive gear
1632-15 to move from the accommodated position (stand-by position) to the
projecting position (operating position), the torque limiter 1632-14 slips, so that
any more driving force is not received, by which the movable member 1652R
stops at the projecting position.
[0722] With the above structure, the vertical movement of the movable
member 1652R which may occur when the rack portion 1652Rx end of the
movable member 1652R and the gear portion 1632-15b of the movable member
drive gear 1632-15 make the intermittent contact is suppressed, and therefore, the
projecting position of the movable member 1652R can be stabilized and noise can
be suppressed.
[0723] Next, the operation of moving the movable member 1652R from the
projecting position to the accommodated position will be described. As shown
in Figure 104, in a state where the movable member 1652R is located at the
projecting position, in interrelation with the shifting of the front door 11 of the
image forming apparatus main assembly 170 described above from the closed
state to the open state, the development drive coupling 185 on the main assembly
side moves in the direction of arrow Y2 in Figure 109.Along with this, by the
development coupling gear 1632-11 moving in the direction of arrow Y2 by the
urging force of the compression spring 1632- 12, the clutch plate 1632-13 is
disengaged (state in part (a) of Figure 109). That is, the movable member drive
gear 1632-15 is in an independent state in which it does not rotate integrally with
the other gears of the drive input gear unit 1632-1. By this, since the rack
portion 1652Rx of the movable member 652R meshes with the independent
movable member driving gear 1632-15, it can move substantially parallel to the direction of arrow Z Iin Figure 104 by the urging force of the tension spring 153.
When this operation is completed, the movable member 1652R does not project
from the developing unit 1609 and is placed at the accommodated position
(stand-by position) (state in Figure 103).
[0724] In this embodiment, the torque limiter 1632-14 is provided in the
development drive input gear unit 1632-1 as a mechanism for moving the
movable member 1652R, but by allowing the above-mentioned movable member
to move up and down, the cost reduction may be accomplished (see Figure 110).
Figure 110 is a schematic cross-sectional view of the development drive input
gear 1632-2 in which various functional portions of the development drive input
gear unit 1632-1 are integrally molded. In Figures 108 and 109, the coupling
portion 1632-11a, the cylindrical portion 1632-11b, the developing roller drive
gear 1632-11c, the movable member drive gear 1632-15, the transfer roller drive
gear 1632-16b, the stirring drive gear 1632-16c are integrated as a coupling
portion 1632-2a, a cylindrical portion 1632-2b, a developing roller drive gear
1632-2c, a movable member drive gear 1632-2d, a feed roller drive gear 1632-2e,
and a stirring drive gear 1632-2f, respectively. With such a structure, the
movable member 1652R may be structured so as to be moved to the
accommodated position by backlash in each of the development drive input gear
1632-2, the main assembly side development coupling 185, and a plurality of
gears (not shown) which drive the main assembly side development coupling 185.
Also, in the structure using the above-mentioned torque limiter 1632-14, the
movement to the accommodated position may be effected by the backlash.
[0725] Further, in this embodiment, as a mechanism for moving the movable
member 1652R between the projecting position and the accommodated position,
the movable member drive gear 1632-15 for driving the movable member 1652R
is provided on the driving shaft (same as the swinging shaft K) for transmitting the rotational driving force from the image forming apparatus main assembly 170 to the developing unit 1609, but the present invention is not limited to such an example. Such an example thereof is shown in Figure 111. Part (a) of Figure
11 and part (b) of Figure 11 is a view of the process cartridge 1600 as viewed
from the non-drive-side thereof when the movable member 1632R-3 is located at
the accommodated position, omitting the members except for the drive-side
cartridge cover member 1616, the development cover member 1628, the
development coupling gear 1632-11, the movable member drive gear unit 1652R
3, the movable member 1652R-3 and the spacer 151R The movable member
drive gear unit 1632-3 is structured such that the movable member drive gear
1632-33 is arranged by way of the first intermediate gear 1632-31 and the second
intermediate gear 1632-32. The movable member drive gear 1632-33 is
arranged so as to engage with the rack portion 1652Rx-3 of the movable member
1652R-3. With the above structure, the first intermediate gear 1632-31, the
second intermediate gear 1632-32 and the rotatable member drive gear 1632-33
rotate in interrelation with the development coupling gear 1632-11 rotating in the
arrow D1 direction to move the movable member drive 1652R-3 to the projecting
position (see part (b) of Figure 111), as described above the. Further, the
movement from the projecting position to the accommodated position is the same
as described above. As described above, the movable member drive gear for
moving the movable member does not have to be provided on the swing axis K.
[0726] In addition, in this embodiment, the developing roller drive gear 1632
11c (1632-2c), the movable member drive gear 1632-15 (1632-2d), the transfer
roller drive gear 1632-16b (1632-2e), and the stirring drive gear 1632-16c (1632
2f) are arranged in the order named in the direction from the upstream side
toward the downstream side direction of the arrow Y1 in the from the drive-side
end of the process cartridge 1600 upstream direction to the downstream, but the arrangement of various gears is not limited to this example, and the number of gear teeth and the tooth profile are not limited to such an example. Further, various gears may share a function, and for example, the developing roller drive gear 1632-2c may be given the function of the movable member drive gear 1632
2d, and the rack portion 1652Rx of the movable member 1652R is engaged with
the developing roller drive gear 1632-2c so that the movable member 1652R is
moved.
[0727] Next, referring to Figures 112 to 113, the separation/contact mechanism 1650L on the non-drive-side of the process cartridge 1600 in this
embodiment will be described. Similarly to the drive-side separation/contact
mechanism 1650R, the separation/contact mechanism 1650L includes a spacer
151L which is a restricting member, a movable member 1652L which is a
pressing member, and a tension spring 153 (see Figure 112). Themovable
member 1652L is provided with a rack portion 1652Lx, and is supported by a
non-drive-side bearing so as to be linearly movable and rotatable. The rack
portion 1652Lx is structured to engage with the non-drive-side movable member
drive gear 1635 and is movable in interrelation with the rotation of the non-drive
side movable member driving gear 1635. The non-drive-side movable member
drive gear 1635 is connected with the penetrating shaft (see Figure 113), and the
penetrating shaft 1636 is connected with the development drive input gear unit
1632-1 by way of a penetrating shaft gear (not shown). By this, when the
development drive input gear unit 1632-1 receives a driving force from the main
assembly side development coupling 185 and rotates, and in interrelation with this, the penetrating shaft 1636 rotates, and the non-drive-side movable member
drive gear 1635 rotates, I which the movable member 1652L moves. As long as
the penetrating shaft 1636 has the shaft which communicates between the drive
side and the non-drive-side of the process cartridge 1600, a toner feeding roller
1016 or a developing roller 106, for example, may be used, or may be further
added.
[0728] The operation of contacting and separating the photosensitive member
drum 104 and the developing roller 106 by the separation/contact mechanism
1650L is the same as those of the above-mentioned separation/contact mechanism
1650R on the drive-side.
[0729] As for the separation/contact mechanism in this embodiment, the
separation/contact mechanism of the process cartridge 1600 may be provided on
only one side as in the Embodiment 2. Figures 114 and 115 are perspective
views of the process cartridge 1600 in a state where the movable member 1652 is
projected to the projecting position by receiving the rotational driving force from
the development coupling 185 on the main assembly side, and Figure 114 is a
view in which the separation/contact mechanism 1650R is provided only on the
drive-side, and Figure 115 is a view in which the separation/contact mechanism
1650L is provided only on the non-drive-side.
[0730] According to the structure of this embodiment described above, the
same effect as that of the Embodiment 1 can be provided.
[0731] Further, in this embodiment, the movable member 1652R is moved by
rotating the coupling portion (coupling member) 1632-11a by inputting a driving
force. By the movement of the movable member 1652R, the first force
receiving portion (retracting force receiving portion, separating force receiving
portion) 1652Rk and the second force receiving portion (contact force receiving
portion) 1652Rn are moved between the accommodated position (stand-by
position) and the projecting position (operating position). With such a structure,
it is possible to control the movement of the movable member 1652R depending
on whether or not a driving force is input to the coupling portion (coupling
member) 1632-11a.
<Embodiment 8>
[0732] Next, referring to Figures 116 to 128, Embodiment 8 will be described.
[0733] In this embodiment, structures and operations different from those of the above-described embodiment will be mainly described, and description of similar structures and operations will be omitted. Further, for the structure
corresponding to the above-described embodiment, the same reference numerals
and characters are assigned, or the reference numerals in the first part is changed
while the reference numerals and characters in the second part are the same.
[0734] The process cartridge 1900 includes a separation/contact mechanism
1950R (see Figure 116) on the drive-side and a separation/contact mechanism
1950L (see Figure 126) on the non-drive-side. Regarding the separation/contact
mechanism, the details of the separation/contact mechanism 1950R on the drive
side will first be described, and then the separation/contact mechanism 1950L on
the non-drive-side will be described. Further, since the separation/contact mechanism has almost the same function on the drive-side and the non-drive-side,
R is added to the reference sign of each member on the drive-side, and L is added
to the reference sign of each member is driven on the non-drive-side.
[0735] In this embodiment, the movable member 1952R corresponding to the movable member 152R in the Embodiment 1 avoids the separation control
member 196R in the longitudinal direction (arrow Y2 direction) in the process of
insertion and removal of the process cartridge 1900 into and from the image
forming apparatus main assembly 170, as shown in Figure 120 Further, when the
mounting is completed, the movable member 1952R is in the same longitudinal
position as the separation control member 196R, so that the contact separation
operation can be performed as in the Embodiment 1. The insertion and removal
while the movable member avoids the separation control member 196R will be described hereinafter.
[Drive-side process cartridge structure]
[0736] Figure 116 shows an assembly perspective view of the drive-side of the developing unit 1909 including the separation/contact mechanism 1950R. The
separation/contact mechanism 1950R includes a spacer 1951R which is a restricting member (holding member), a movable member 1952R which is a
pressing member, and a tension spring 1953. In this embodiment, the movable
member 1952R is provided with a first oblong round hole 1952Rx and a second
oblong round hole 1952Ry (see part (c) of Figure 117), and an outer diameter of a
second supporting portion 1928k of the development cover member 1928 is fitted
with the inner walls of the oblong round hole 1952Rx and the second oblong
round hole 1952Ry, so that the movable member 1952R is swingably supported
about two swing axes which will be described hereinafter.
[0737] Further, similarly to the Embodiment 1, the inner diameter portion of the support receiving portion 1951Ra of the spacer 1951R is fitted with the first supporting portion 1928c of the development cover member 1928, the spacer
1951R is rotatably supported, and the movable member 1952R and the spacer
1951R are urged to attract each other by the tension spring 1953. Further, the
outer diameter portion of the cylindrical portion 1928b of the development cover
member 1928 is fitted into the developing unit supporting hole 1916a of the
drive-side cartridge cover member 1916, the developing unit 1909 is supported so
as to be rotatable about the swing axis K.
[Structure and operation of movable member]
[0738] Next, referring to Figures 117 to 119, the structure of the movable member 1952R on the drive-side in this embodiment will be described in detail.
[0739] Part (a) of Figure 117 is a front view of the movable member 1952R per se as viewed from the longitudinal direction of the process cartridge 1900 (in the direction of arrow Y1 in Figure 116), and part (b) of Figure 117 and part (c) of Figure 117 is a perspective view of the movable member 1952R per se. The movable member 1952R is provided with a first oblong round hole 1952Rx and a second oblong round hole 1952Ry. Here, the longitudinal directions (LH) of the oblong round hole shapes of the first oblong round hole 1952Rx and the second oblong round hole 1952Ry are the same, the upward direction (approximately ZI direction) is the arrow LH1, and the downward direction (approximately Z2 direction) is the arrow LH2. In addition, the axis perpendicular to the LH direction and perpendicular to the depth direction (Y1 direction) of the oblong round hole forming the first oblong round hole 1952Rx is axis HXR. The movable member 1952R has a cylindrical surface 1952Rz extending around an axis HXR. The Y1 direction is parallel to the rotation axis M2 of the developing roller 106 and the rotation axis M1 of the photosensitive drum 104 described in the Embodiment 1. In this embodiment, the first oblong round hole 1952Rx and the second oblong round hole 1952Ry are arranged so as to have a common apex in the direction of arrow LH1. Further, the first oblong round hole 1952Rx and the second oblong round hole 1952Ry communicate with each other, and the diameter of the first oblong round hole 1952Rx is selected to be larger than that of the second oblong round hole 1952Ry. In addition, the length of the first oblong round hole 1952Rx is selected to be larger than the length of the second oblong round hole 1952Ry.
[0740] Further, in the movable member 1952R, as in the Embodiment 1, a
projecting portion 1952Rh is formed on the downstream side of the first oblong
round hole 1952Rx in the arrow LH2 direction. A first force receiving surface
1952Rm and a second force receiving surface 1952Rp having an arc shape are
provided on the projecting portion 1952Rh. The first force receiving surface
1952Rm and the second force receiving surface 1952Rp are the first force receiving portion (retracting force receiving portion, separating force receiving portion) and the second force receiving portion (contacting force applying portion) as in the Embodiment 1. On the other hand, the movable member
1952R has an arc-shaped pressed surface 1952Rf on the downstream side in the
direction of the arrow LH1. Further, the movable member 1952R is provided
with a spring-hooked portion 1952Rs to which the tension spring 1953 is
mounted, a first pressing surface 1952Rq, and a second pressing surface 1952Rr,
as in the Embodiment 1.
[0741] Part (a) of Figure 118 is a perspective view illustrating only the
development cover member 1928, and part (b) of Figure 118 is a perspective
view illustrating the development cover member 1928 and the movable member
1952R. The second supporting portion 1928k of the development cover
member 1928 is formed by a first cylindrical portion 1928 kb, a second swing
portion 1928 ka having a spherical surface, and a second cylindrical portion 1928
kc having a diameter smaller than that of thefirst cylindrical portion 1928 kb.
Here, the axis passing through the center of the first cylindrical portion 1923 kb
and the second cylindrical portion 1928 kc is HYR. The axis perpendicular to
this HYR and passing through the spherical center of the second swingable
portion 1928ka is the same as the above-mentioned HXR. In this embodiment,
the second swingable portion 1928ka has the spherical surface, but this is not
limiting and it will suffice if swinging of the movable member 1952R in the
directions of arrows YA and YB (see Figure 119) and swinging in the directions
of arrows BA and BB (see Figure 119) as will be described hereinafter are not
hindered. It is not limited to this as long as it is a surface that is set within a
range that does not interfere with. In addition, the diameters of the first oblong
round hole 1952Rx and the second oblong round hole 1952Ry of the movable
member 1952R and the positional relation in the direction of LH is not limited to this example, and it will suffice if the swinging in the directions of the arrows YA,
YB and in the directions of arrows BA, BB with respect to the first cylindrical
portion 1928 kb and the second cylindrical portion 1928 kc are not hindered.
[0742] Figure 119 shows a state in which the separation/contact mechanism
1950R is mounted on the development cover member 1928. Part (a) of Figure
119 is a view as seen in the longitudinal direction of the process cartridge 1900
(in the direction of arrow Y2 in Figure 116). The longitudinal direction of the
process cartridge 1900 is a direction parallel to the rotation axes M1, M2, and K
described in the previous embodiment. The movable member 1952R is
supported by the second supporting portion 1928k of the development cover
member 1928 so as to be swingable in the directions of arrows BA and BB about
HYR as in the Embodiment 1.
[0743] A cross-section taken along a line passing through the center (HYR) of
the second supporting portion 1928k and parallel to the above-mentioned LH
direction is shown in part (b) of Figure 119 as a QQ cross-section. Themovable
member 1952R receives a force in the Fl direction by the tension spring 1953 in
a state that the second swingable portion 1928ka and the inner wall of the first
oblong round hole 1952Rx are in contact with each other. Here, the spring
hooked portion 1952Rs of the movable member 1952R is placed downstream, in
the Y2 direction, of the contact point between the second swingable portion
1928ka and the first oblong round hole 1952Rx, and therefore, the spring force
produces a moment about the axis HXR by the spring force in the arrow YA
direction about on the axis HXR. The attitude of the movable member 1952R
swinging in the direction of arrow YA is determined by contacting to the
movable member restriction portion 1928s of the development cover member
1928, and the projecting portion 1952Rh projects in the Y2 direction. This
position is a stand-by position of the movable member 1952R.
[0744] Next, when the pressed surface 1952Rf is pushed in the direction of
arrow ZA from the state shown in part (b) of Figure 119, it is placed downstream,
in the Y2 direction, of the contact point between the second swingable portion
1928ka and the first oblong round hole 1952Rx, and therefore, a moment is
produced in the direction of the arrow YB about the axis HXR. The projecting
portion 1952Rh of the movable member 1952R moves in the Y1 direction so as
to take the attitude shown in part (c) of Figure 119. This position is an operating
position of the movable member 1952R. The amount of pushing in the ZA
direction is determined by the amount of movement of the cartridge pressing unit
191 of the image forming apparatus main assembly (not shown) in the ZA
direction.
[0745] In order to restrict the movable member 1952R in rotating around the
axis HYR and the axis HZR perpendicular to the axis HXR, the cylindrical
surface 1952Rz contacts the regulation surface 1926d (see Figure 116) of the
drive-side bearing 1926 (not shown). In addition, the contact between the
second cylindrical portion kc and the second oblong round hole 1952 Ry has the
same rotation restricting effect.
[0746] With the above structure, the movable member 1952R is supported so
as to be swingable in two directions about the shaft HYR and the shaft HXR.
[Mounting of process cartridge to image forming apparatus main assembly]
[0747] Next, referring to Figures 120 and 121, the description will be made as
to the engaging operation of the separation/contact mechanism 1950R of the
process cartridge 1900 and the development separation control unit 195 of the
image forming apparatus main assembly 170 at the time when the process
cartridge 1900 is mounted on the image forming apparatus main assembly 170
(not shown).
[0748] Figure 120 is a view (part (a) of Figure 120) of the image forming apparatus M as viewed from the front door side, and a view (part (b) of Figure
120) of the process cartridge 1900 as viewed from the drive-side of the process
cartridge 1900 with omission except for the process cartridge 1900, the cartridge
pressing unit 191 and the separation control member 196R, at the time when the
process cartridge 1900 is mounted on the cartridge tray 171 (not shown) of the
image forming apparatus main assembly 170 and the cartridge tray is inserted
into the first mounting position. The projecting portion 1952Rh of the movable
member 1952R is placed at the stand-by position in which it has swung in the YA
direction as described above when the cartridge tray 171 is inserted into the first
mounting position. Therefore, the separation control member 196R can be
inserted into the first mounting position as in the Embodiment 1 because it is
retracted from the separation control member 196R in the direction of the arrow
Y2. Further, at the first mounting position, the movable member 1952R is
provided so that the projecting portion 1952Rh is accommodated in the space
196Rd of the separation control member 196R as viewed from the drive-side of
the process cartridge as shown in part (b) of Figure 120.
[0749] As in Embodiment 1, in interrelation with the transition of the front
door 11 of the image forming apparatus main assembly 170 from the open state to
the closed state, the cartridge pressing unit 191 lowers in the direction of arrow
ZA and the first force applying portion 191a is brought into contact with the
pressed surface 1952Rf of the movable member 1952R. Thereafter, when the
cartridge pressing unit 191 is lowered to a predetermined position which is the
second mounting position, the projecting portion 1952Rh of the movable member
1952R swings in the YB direction by the above-mentioned swing mechanism and
reaches the operating position (state of Figure 121). When this operation is
completed, the first force application surface 196Ra of the separation control
member 196R and the first force receiving surface 1952Rp of the movable member 1952R oppose each other as in the Embodiment 1, and the second force application surface 196Rb and the second force receiving surface 1952 Rm oppose each other. That is, in the directions of arrows Y1 and Y2, the projecting portion 1952Rh of the movable member 1952R and a portion of the separation control member 196R are overlapped each other.
[0750] When the process cartridge 1900 is removed from the image forming
apparatus main assembly 170, the operation is opposite to the operation at the
time of mounting, and the projecting portion 1952Rh of the movable member
1952R moves from the operating position to the stand-by position.
[Contact/separation operation of developing unit]
[0751] The contact/separation operation in this embodiment is the same as that
in the Embodiment 1 as will be described below.
[0752] Figure 122 shows a state in which the developing unit 1909 is placed at
a separated position. When the separation control member 196R moves in the
W42 direction from this state, the second force application surface 196Ra of the
separation control member 196R and the second force receiving surface 1952Rp
of the movable member 1952R come into contact with each other, and the
movable member 1952R swings in the direction BB about the HYR. Further, as
the movable member 1952R rotates, the spacer 1951R is rotated in the B2
direction while the second pressing surface 1952Rr of the movable member
1952R is in contact with the second pressed surface 1951Re of the spacer 1951R.
Then, the spacer 1951R is rotated by the movable member 1952R to the
separation release position (second position) where the contact surface (contact
portion) 1951Rc (not shown) and the contact surface (non-contact portion) 116c
are separated from each other. By this, the developing unit 1909 can move from
the separated position to the contacting position where the developing roller 9 and
the photosensitive member drum 104 contact each other (state in Figure 123).
[0753] Thereafter, the separation control member 196R moves in the direction
of W41 and returns to the home position (state in Figure 124).
[0754] When the image forming operation is completed and the separation
control member 196R moves in the W41 direction, the first force application
surface 196Rb and the first force receiving surface 1952Rm come into contact
with each other, and the first pressing surface 1952Rq of the movable member
1952R contacts the pressed surface 1926c of the drive-side bearing 1926, by
which the developing unit rotates from the contact position in the direction of
arrow VI about the swing axis K (state in Figure 125).
[0755] Thereafter, the separation control member 196R moves in the direction
of W42 and returns to the home position, so that the spacer 1951R shifts to the
separation holding position (first position) (state in Figure 122).
[Non-drive-side process cartridge structure]
[0756] Next, referring to Figure 126, the separation/contact mechanism 1950L
on the non-drive-side of the process cartridge 1900 in this embodiment will be
described. Figure 126 shows an assembly perspective view of the non-drive
side of the developing unit 1909 including the separation/contact mechanism
1950L. Similarly to the drive-side separation/contact mechanism 1950R, the
separation/contact mechanism 1950L includes a spacer 1951L which is a
restricting member, a movable member 1952L which is a pressing member, and a
tension spring 1953. Further, the movable member 1952L is provided with a
first oblong round hole 1952Lx and a second oblong round hole 1952Ly (not
shown), and an outer diameter portion of the second supporting portion 1927e of
the non-drive-side bearing 1927 and the inner walls of the first oblong round hole
1952Lx and the first oblong round hole 1952Ly are fitted with each other. In
addition, it is supported so as to be swingable about the two swinging shafts,
namely, the shaft HXRL and the shaft HYRL.
[0757] Further, as in the Embodiment 1, the inner diameter portion of the
support receiving portion 1951La of the spacer 1951L is fitted with the inner
diameter portion of the first supporting portion 1927b of the non-drive-side
bearing 1927, so that the spacer 1951L is rotatably supported, and the movable
member 1952R and the spacer 1951L are urged to attract each other by the
tension spring 1953. Further, the outer diameter portion of the cylindrical
portion 1927a of the non-drive-side bearing 1927 is fitted into the developing unit
supporting hole 1917a of the non-drive-side cartridge cover member 1917, so that
the developing unit 1909 rotates about the swing axis K.
[Contact/separation operations of developing unit]
[0758] The operation of contacting and separating the photosensitive member
drum 104 and the developing roller 106 by the separation/contact mechanism
1950L is the same as that of the above-mentioned separation/contact mechanism
1950R on the drive-side.
[0759] As for the separation/contact mechanism in this embodiment, the
separation/contact mechanism of the process cartridge 1900 may be disposed on
only one side as in the Embodiment 2. Figure 127 shows a structure in which
the separation/contact mechanism 1950R is provided only on the drive-side, and
Figure 128 shows a structure in which the separation/contact mechanism 1950L
is provided only on the non-drive-side. However, it is necessary to
appropriately set the spacing amount within a range of not affecting the image
formation.
[0760] According to the structure of this embodiment described above, the
same effect as that of the Embodiment 1 can be provided.
[0761] Further, in this embodiment, the projecting portion 1952Rh including
the first force receiving surface 1952Rm constituting the first force receiving
portion (retracting force receiving portion, separation force receiving portion) and the second force receiving surface 1952R constituting the second force receiving portion (contact force receiving portion) is movable in the YA direction. In this embodiment, by the movement thereof, the projection 1952Rh, the first force receiving surface 1952Rm, and the second force receiving surface 1952Rp are displaced at least in the Y2 direction (direction parallel to the rotation axis M1 and the rotation axis M2 of the Embodiment 1). By this, when the process cartridge 600 is inserted or removed into the apparatus main assembly 170, it can be avoided that the projecting portion 1952Rh, particularly the first force receiving surface 1952Rm and the second force receiving surface 1952Rp, and the apparatus main assembly 170, particularly the separation control member
196R interfere with each other, are engaged.
[0762] Further, in this embodiment, the amount of movement of the projecting
portion 1952Rh in the pressing direction (ZA direction) of the pressing unit 191
at the time when the projecting portion 1952Rh moves from the stand-by position
to the operating position, is small. Therefore, it is possible to set a small amount
of movement of the pressing unit 191 required for the projecting portion 1952Rh
to move from the stand-by position to the operating position, and further
downsizing of the image forming apparatus main assembly 170 can be realized.
<Embodiment 9>
[0763] Hereinafter, Embodiment 9 disclosure will be described with reference
to the drawings. In this embodiment, for the structure corresponding to the
above-described Embodiment 1, the same reference numerals and characters are
assigned, or the reference numerals in the first part is changed while the reference
numerals and characters in the second part are the same.
[0764] In the following embodiment, an image forming apparatus in which
four cartridges (hereinafter referred to as process cartridges) can be mounted and dismounted is illustrated as an image forming apparatus. The number of process cartridges mounted on the image forming apparatus is not limited to this example.
It is selectable appropriately as needed. Further, in the embodiment described
below, a laser beam printer is exemplified as one aspect of the image forming
apparatus.
[Outline of structure of image forming apparatus]
[0765] Figure 130 is a schematic sectional view of the image forming
apparatus 500. Figure 131 is a cross-sectional view of the process cartridge P.
Further, Figure 132 is an exploded perspective view of the process cartridge P as
viewed from the drive-side, which is one end side in the direction of the rotation
axis of the photosensitive drum 4 (hereinafter referred to as the longitudinal
direction).
[0766] The image forming apparatus 500 is a four-color full-color laser printer
using an electrophotographic process, and forms a color image on the recording
material S. The image forming apparatus 500 is a process cartridge type, and
the process cartridge is dismountably mounted to the image forming apparatus
main assembly 502 to form a color image on the recording material S.
[0767] Here, regarding the image forming apparatus 500, the side where the
front door 111 is provided is the front surface (front surface), and the surface
opposite to the front surface is the back surface (rear surface). Further, the right
side of the image forming apparatus 500 as viewed from the front is referred to as
a drive-side, and the left side is referred to as a non-drive-side. Further, as the
image forming apparatus 500 is viewed from the front, the upper side is the upper
surface and the lower side is the lower surface. Figure 130 is a cross-sectional
view of the image forming apparatus 500 as viewed from the non-drive-side,
wherein the front side of the sheet of the drawing is the non-drive-side, the right
side of the sheet of the drawing is the front side of the image forming apparatus
500, and the rear side of the sheet of the drawing is the drive-side of the image
forming apparatus 500.
[0768] In the image forming apparatus main assembly (apparatus main assembly) 502, four process cartridges P (PY, PM, PC, PK)) namely, a first
process cartridge PY, a second process cartridge PM, a third process cartridge PC, and a fourth process cartridge PK are arranged in a substantially horizontal
direction.
[0769] Each of the first to fourth process cartridges P (PY, PM, PC, PK) includes the same electrophotographic process mechanism, but the color of the
developer (hereinafter referred to as toner) is different. Rotational driving
forces are transmitted to the first to fourth process cartridges P (PY, PM, PC, PK)
from the drive output portion (not shown) of the image forming apparatus main
assembly 502.
[0770] Further, a bias voltage (charging bias voltage, development bias voltage, and so on) is supplied from the image forming apparatus main assembly 502 to each of the first to fourth process cartridges P (PY, PM, PC, PK).
[0771] As shown in Figure 131, each of the first to fourth process cartridges P (PY, PM, PC, PK) of this embodiment includes a drum unit (photosensitive
member unit, first unit) 8. The drum unit 8 rotatably supports the photosensitive
drum 4, and includes a charging member and a cleaning member as process
means acting on the photosensitive drum 4. The photosensitive drum 4 is a
tubular photosensitive member having a photosensitive layer on the outer
peripheral surface.
[0772] Further, each of the first to fourth process cartridges P (PY, PM, PC, PK) includes a developing unit (second unit) 9 provided with a developing
member for developing an electrostatic latent image on the photosensitive drum 4.
The drum unit 8 and the developing unit 9 are coupled to each other. A more specific structure of the process cartridge P which will be described hereinafter.
[0773] The first process cartridge PY contains yellow (Y) toner in the developing container 25, and forms a yellow toner image on the surface of the
photosensitive drum 4. The second process cartridge PM contains magenta (M)
toner in the developing container 25, and forms a magenta-colored toner image on the surface of the photosensitive drum 4. The third process cartridge PC
contains the cyan (C) toner in the developing container 25, and forms a cyan
colored toner image on the surface of the photosensitive drum 4. The fourth
process cartridge PK contains black (K) toner in the developing container 25, and
forms a black toner image on the surface of the photosensitive drum 4.
[0774] A laser scanner unit 114 as an exposure means is provided above the first to fourth process cartridges P (PY, PM, PC, PK). The laser scanner unit
114 outputs the laser beam U corresponding to the image information. Thelaser
beam U passes through the exposure window 10 of the process cartridge P and
scans and exposes the surface of the photosensitive drum 4.
[0775] An intermediary transfer belt unit 112 as a transfer member is provided below the first to fourth process cartridges P (PY, PM, PC, PK). The
intermediary transfer belt unit 112 includes a drive roller 112e, a turn roller 112c,
a tension roller 112b, and a flexible transfer belt112a extended around.
[0776] The lower surface of the photosensitive drum 4 of each of the first to
fourth process cartridges P (PY, PM, PC, PK) is in contact with the upper surface
of the transfer belt 112a. The contact portion is the primary transfer portion.
Inside the transfer belt 112a, a primary transfer roller 112d is provided so as to
oppose the photosensitive drum 4. The secondary transfer roller 106a contacts
the turn roller 112c with the transfer belt112a therebetween. The contact
portion between the transfer belt 112a and the secondary transfer roller 106a is
the secondary transfer portion.
[0777] A feeding unit 104 is provided below the intermediary transfer belt unit
112. The feeding unit 104 includes a sheet feed tray 104a on which the
recording material S is loaded and accommodated, and includes a sheet feed
roller 104b.
[0778] A fixing device 107 and a paper discharge device 108 are provided on
the upper left side of the image forming apparatus main assembly 502 in Figure
130. The upper surface of the image forming apparatus main assembly 502
functions as a paper discharge tray 113.
[0779] The toner image of the recording material S is fixed by the fixing
means provided in the fixing device 107, and the toner image is discharged to the
paper discharge tray 113.
[Image forming operation]
[0780] The operation for forming a full-color image is as follows. The
photosensitive drum 4 of each of the first to fourth process cartridges P (PY, PM,
PC, PK) is rotationally driven at a predetermined speed (in the direction of arrow
A in Figure 131). The transfer belt 112a is also rotationally driven in the
forward direction (direction of arrow C in Figure 130) relative to the rotation of
the photosensitive drum at a speed corresponding to the speed of the
photosensitive drum 4.
[0781] The laser scanner unit 114 is also actuated. In synchronization with
the operation of the laser scanner unit 114, the charging roller 5 uniformly
charges the surface of the photosensitive drum 4 to a predetermined polarity and
potential in each process cartridge. The laser scanner unit 114 scans and
exposes the surface of each photosensitive drum 4 with laser beam U in
accordance with the image signals of corresponding color. By this, an
electrostatic latent image corresponding to the image signal of the corresponding
color is formed on the surface of each photosensitive drum 4. The formed electrostatic latent image is developed by a developing roller 6 which is rotationally driven at a predetermined speed (in the direction of arrow D in Figure
131).
[0782] By the electrophotographic image forming process operation as
described above, a yellow toner image corresponding to the yellow component of
the full-color image is formed on the photosensitive drum 4 of the first process
cartridge PY. Then, the toner image is first transferred onto the transfer belt
112a. Similarly, a magenta color toner image corresponding to the magenta
component of the full color image is formed on the photosensitive drum 4 of the
second process cartridge PM. Then, the toner image is superimposed on the
yellow toner image already transferred on the transfer belt 112a and first
transferred. Similarly, a cyan toner image corresponding to the cyan component
of the full-color image is formed on the photosensitive drum 4 of the third
process cartridge PC. Then, the toner image is superimposed on the yellow
colored and magenta-colored toner images already transferred on the transfer belt
112a and first transferred. Similarly, a black toner image corresponding to the
black component of the full-color image is formed on the photosensitive drum 4
of the fourth process cartridge PK. Then, the toner image is superimposed on
the yellow, magenta, and cyan toner images already transferred on the transfer
belt 112a and first transferred. In this manner, a four-color full-color unfixed
toner image of yellow, magenta, cyan, and black is formed on the transfer belt
112a.
[0783] On the other hand, the recording materials S are separated and fed one
by one at a predetermined control timing. The recording material S is
introduced into the secondary transfer portion, which is the contact portion
between the secondary transfer roller 106a and the transfer belt 112a, at a
predetermined control timing. By this, in the process of transporting the recording material S to the secondary transfer portion, the four-color superimposed toner image on the transfer belt 112a is collectively transferred onto the surface of the recording material S.
[Overall structure of process cartridge]
[0784] In this embodiment, the first to fourth process cartridges P (PY, PM,
PC, PK) have the equivalent structure, but the colors of the contained toners are
different. The process cartridge P includes a photosensitive drum 4 (4Y, 4M,
4C, 4K) and a process means which actable on the photosensitive drum 4. Here,
examples of the process means are the charging means for charging the
photosensitive drum 4, the developing means for developing the latent image
formed on the photosensitive drum 4 by adhering toner to the photosensitive
drum 4, and the cleaning means for removing residual toner remaining on the
surface of the photosensitive drum 4. In this embodiment, the charging means
(charging member) is a charging roller 5, the developing means (developing
member) is a developing roller 6, and the cleaning means (cleaning member) is a
cleaning blade 7. The process cartridge P is divided into a drum unit 8 (8Y, 8M,
8C, 8K) and a developing unit 9 (9Y, 9M, 9C, 9K). The developing roller 6
carries the toner on the surface thereof.
[Drum unit structure]
[0785] As shown in Figures 131 and 132, the drum unit 8 includes the
photosensitive drum 4, the charging roller 5, the cleaning blade 7, a waste toner
container 15, aa waste toner storing portion 15a, a drive-side cartridge cover
member 520, and a non-drive-side cartridge cover member 521. The
photosensitive drum 4 is supported, so as to be rotatable about the axis (rotational
axis) M1, by a drive-side cartridge cover member 520 and a non-drive side
cartridge cover member 521 provided at both ends in the longitudinal direction of
the process cartridge P. Further, as shown in Figure 132, one longitudinal end side of the photosensitive drum 4 is provided with a photosensitive member coupling member 43 (fixed thereto) for receiving a driving force for rotating said photosensitive drum. The photosensitive member coupling member 43 is engaged with the coupling (not shown) as the drum drive output portion of the image forming apparatus main assembly 502 to be rotated by the driving force of the driving motor (not shown) of the image forming apparatus main assembly 502 about the rotational axis which is coaxial with the axis M1 The charging roller 5 is supported by the waste toner container 15 so that it is rotated by the photosensitive drum 4 in contact therewith. Further, the cleaning blade 7 is supported by the waste toner container 15 so as to contact the peripheral surface of the photosensitive drum 4 at a predetermined pressure. The untransferred residual toner removed from the peripheral surface of the photosensitive drum 4 by the cleaning blade 7 is stored in the waste toner storing portion 15a in the waste toner container 15. Of the drum unit (first unit) 8, the waste toner container 15, the drive-side cartridge cover member 520, and the non-drive-side cartridge cover member 521 constitute a drum frame (first frame).
[Developing unit structure]
[0786] As shown in Figure 131, the developing unit 9 includes the developing roller (developing member) 6, a developing blade 30, the developing container 25,
the development cover member 533, a stirring member 29a (not shown), a toner
feeding roller 70 (not shown), and so on. The developing container 25 includes
a toner accommodating portion 29 for storing toner to be supplied to the
developing roller 6, and supports a developing blade 30 for regulating the toner
layer thickness (thickness of the toner layer) on the peripheral surface of the
developing roller 6. The developing blade 30 includes an elastic member 30b
which is a sheet-like metal having a thickness of about 0.1 mm, and a member
30a which is a metal material having and an L-shaped cross-section to which the elastic member 30b is mounted by welding or the like and which is supported by the developing container 25. The developing blade 30 forms a toner layer having a predetermined thickness between the elastic member 130b and the developing roller 106. The developing blade 30 is mounted on the developing container 25 with fixing screws 30c at two locations at each of one end side and the other end side in the longitudinal direction. The developing roller 6 includes a core metal 6c and a rubber portion 6d. The developing roller 6 is supported rotatably about the axis (rotating axis) M2 by the drive-side bearing 526 and the non-drive-side bearing 27 mounted to the opposite ends in the longitudinal direction of the developing container 25. The stirring member 29a rotates to stir the toner in the toner accommodating portion 29. The toner feed roller
(developer agent supply member) 70 contacts the developing roller 6 and supplies
toner to the surface of the developing roller 6 while also scraping the toner off the
surface of the developing roller 6.
[0787] Further, as shown in Figure 132, a development coupling member 74 for receiving a driving force for rotating the developing roller 6 is provided on
one end side of the developing unit 9 in the longitudinal direction. The
development coupling member 74 engages with a main assembly side coupling
member (not shown) as a development drive output portion of the image forming
apparatus main assembly 502 to receive a rotational driving force of the drive
motor (not shown) of the image forming apparatus main assembly 502, thus
rotating about a rotation axis substantially parallel to the axis M2. The driving
force input to the development coupling member 74 is transmitted by a driving
train (not shown) provided in the developing unit 9, so that the developing roller
6 can be rotated in the direction of arrow D in Figure 131. The development
cover member 533 which supports and covers the development coupling member
74 and a gear train (not shown) is mounted to one end side of the developing container 25 in the longitudinal direction. Of the developing unit (second unit)
9, the developing container 25, the drive-side bearing 526, the non-drive-side
bearing 27, and the development cover member 533 constitute the developing
frame (second frame).
[Assembly of drum unit and developing unit]
[0788] Referring to Figure 132, the assembling of the drum unit 8 and the
developing unit 9 will be described. The drum unit 8 and the developing unit 9
are connected with each other by a drive-side cartridge cover member 520 and a
non-drive-side cartridge cover member 521 provided at both ends in the
longitudinal direction of the process cartridge P. The drive-side cartridge cover
member 520 provided on one end side in the longitudinal direction of the process
cartridge P is provided with a supporting hole 520a for permitting swinging
(moving) the developing unit 9. Further, the non-drive-side cartridge cover
member 521 provided on the other end side in the longitudinal direction of the
process cartridge P is provided with a cylindrical support portion 521a for
swingably supporting the developing unit 9. Further, the drive-side cartridge
cover member 520 and the non-drive-side cartridge cover member 521 are
provided with supporting holes 520b and 521b for rotatably supporting the
photosensitive drum 4.
[0789] Here, on one end side, the outer peripheral surface of the cylindrical
portion 533b of the development cover member 533 is fitted into the supporting
hole 520a of the drive-side cartridge cover member 520. On the other end side,
the support portion 521a of the non-drive-side cartridge cover member 521 is
fitted into the hole of the non-drive-side bearing 27. Further, the end portions of
the photosensitive drum 4 in the longitudinal direction are fitted in the supporting
hole 520b of the drive-side cartridge cover member 520 and the supporting hole
portion 521b of the non-drive-side cartridge cover member 521, respectively.
And, the drive-side cartridge cover member 520 and the non-drive-side cartridge
cover member are fixed to the waste toner container 15 by screws or adhesives
(not shown). That is, the drive-side cartridge cover member 520 and the non
drive-side cartridge cover member 521 are integrated with the waste toner
container 15 to constitute the drum unit 8.
[0790] By this, the developing unit 9 is supported by the drive-side cartridge cover member 520 and the non-drive-side cartridge cover member 521 so as to be
movable (rotatable) relative to the drum unit 8 (photosensitive drum 4). Here, an axis connecting the supporting hole 520a of the drive-side cartridge cover
member 520 and the support portion 521a of the non-drive-side cartridge cover
member 521, that is, the rotation center of the developing unit 9 relative to the
drum unit 8 is a swing axis (rotation axis, rotation axis) K. Further, the center
line of the cylindrical portion 533b of the development cover member 533 is
coaxial with the rotation axis of the development coupling member 74, and the
developing unit 9 receives the driving force, at the swing axis K, from the image forming apparatus main assembly by way of the development coupling member
74. That is, the rotation axis of the development coupling member 74 is also the
rotation axis K (swing axis K). When the assembly of the process cartridge P is
completed, the swing axis K, the axis M1, and the axis M2 are substantially
parallel to each other.
[0791] Further, a developing unit urging spring (second unit urging member) 134 is provided between the developing unit 9 and the drum unit 8. The
development pressure spring 134 (see Figure 131) urges the developing unit 9 to
rotate it relative to the drum unit 8 in the direction of arrow V2 (see part (a) of
Figure 129 and part (b) of Figure 129) about the swing axis K. The
development pressure spring 134 urges the developing unit 9 in the direction of
moving it from the separated position toward the developing position. The developing unit urging spring 134 is a coil spring and is an elastic member.
[Process cartridge mounting/dismounting structure]
[0792] Referring to Figures 130, 133 and 134, the cartridge tray (hereinafter
referred to as a tray) 110 which supports the process cartridge will be described in
more detail. Figure 133 is a sectional view of the image forming apparatus 500
in which the tray 110 is inside the image forming apparatus main assembly 502
with the front door 111 open. Figure 134 is a sectional view of the image
forming apparatus 500 in which the tray 110 is outside the image forming
apparatus main assembly 502 with the front door 111 open. As shown in
Figures 133 and 134, the tray 110 is movable relative to the image forming
apparatus main assembly 502 in the arrow X1 direction (pushing direction) and
the arrow X2 direction (pulling direction). That is, the tray 110 is provided so
as to be retractable and insertable with respect to the image forming apparatus
main assembly 502, and the tray 110 is structured to be movable in a substantially
horizontal direction when the image forming apparatus main assembly 502 is
installed on a horizontal surface. Here, the state in which the tray 110 is outside
the image forming apparatus main assembly 502 (state in Figure 134) is referred
to as an outside position. Further, a state in which the tray 110 is inside the
image forming apparatus main assembly 502 with the front door open and the
photosensitive drum 4 and the transfer belt 112a are spaced by a gap Ti (state in
Figure 133) is referred to as a first inner position.
[0793] The tray 110 is provided with a mounting portion 1Oa to which the
process cartridge P can be dismountably mounted at the outer position shown in
Figure 134. Then, each process cartridge P mounted on the mounting portion
11Oa at the outer position of the tray 110 is supported by the tray 110 by the
drive-side cartridge cover member 520 and the non-drive-side cartridge cover
member 521 contacting the mounting portion 110a. Then, in the state where each process cartridge P is placed in the mounting portion 110a, the tray 110 is moved toward the inside the image forming apparatus main assembly 502, that is, the tray 110 is moved from the outer position to the first inner position. At this time, as shown in Figure 133, each process cartridge P moves while maintaining a gap Ti between the transfer belt 112a and the photosensitive drum 4.
Therefore, the tray 110 can move the process cartridge P inside the image
forming apparatus main assembly 502 without contact of the photosensitive drum
4 to the transfer belt 112a. When the tray 110 is placed in the first inner position,
the photosensitive drum 4 and the transfer belt 112a maintain a gap T1.
[0794] Here, the direction perpendicular to the X direction (X1, X2) of the
arrow in Figure 133 and perpendicular to the axis of the photosensitive drum 4 is
referred to as the Z direction (arrows Z1, Z2 in Figure 133). The tray 110 can
be moved from the first inner position in the direction of arrow Z2 in Figure 133
to the second inner position (state in Figure 130) where the photosensitive drum 4
and the transfer belt 112a are in contact with each other to form an image. In
this embodiment, the tray 110 placed at the first inner position moves in the
direction of the arrow Z2 to the second inner position in Figure 133 in
interrelation with the operation of closing the front door 111 in the direction of
the arrow R in Figure 133 from the state where the front door 111 is open.
[0795] As described above, by using the tray 110, a plurality of process
cartridges P can be collectively set at a position inside the image forming
apparatus main assembly 502 where image formation is possible.
[Spacer]
[0796] Subsequently, referring to Figure 135, the structure for contacting and
separating the developing roller 6 included in the developing unit 9 relative to
photosensitive drum 4 and will be described in detail. In the Embodiment 1, the
spacers 51R and 51L are structured to be moved by receiving a force by way of the movable members 52R and 52L, but in the structure of this embodiment, the spacer is capable of receiving the force not through the movable member.
[0797] Part (a) of Figure 135 and part (b) of Figure 135 are perspective views ofthespacer510perse. The spacer (spacer portion) 510 is a space-holding
member for holding the space between the photosensitive drum 4 and the developing roller 6 with a predetermined space, and is a regulating member for
regulating the position of the developing unit 9 relative to the drum unit 8.
[0798] The spacer (holding member) 510 has an annular shape and is provided with a supported hole (supported portion) 510a which is contacted by and is
supported by the supporting portion 533c of the developing frame. The free end
of the projecting portion (holding portion) 51Ob projecting from the supported
hole 510a in the radial direction is provided with a contact surface 51Oc as a
contacting contact portion having an arc surface extending about the axis of the
supported hole 510a, the contact portion being a part of the drum unit 8.
[0799] The projecting portion (holding portion) 51Ob is a portion which connects the supported portion 510a and the contact surface 51Oc with each other,
and has stiffness sufficient to maintain the spaced position of the developing unit
9 while being sandwiched between the drum unit 8 and the developing unit 9.
[0800] Further, it has a restricted surface (restricted portion) 510k adjacent to the contact surface 510c. Furthermore, the spacer 510 is provided with a
projecting portion 51Od projecting in the radial direction of the supported hole
51Oa and a force receiving portion (first force receiving portion, contact force
receiving portion or a pressed portion) 510e) projecting from the projecting
portion 510d along the axial direction of the supported hole 510a. Further,the
spacer 510 includes a main body portion 51Of connected to the supported hole
51Oa, and the main body portion 51Of is provided with a spring-hooked portion
51Og projecting in the axial direction of the supported hole 51Oa and has a first restricted surface 51Oh which is a surface perpendicular to the axial direction of the supported hole 510a.
[Spacer assembly]
[0801] Next, referring to Figures 136, 137, and 129, the assembling of the spacer 510 will be described. Figure 136 is a perspective view of the process cartridge P before assembling the spacer 510 as viewed from the drive-side, and
Figure 137 is a perspective view of the process cartridge P after assembling the
spacer 510 as viewed from the drive-side. Figure 129 is a view of the process
cartridge P after assembling the spacer 510, as viewed from the drive-side along
the swing axis K. Part (a) of Figure 129 shows the developing unit 9 and the
developing frame in the retracted position (separated position), and part (b) of
Figure 129 shows a state in which the developing unit 9 and the developing frame
are in the developing position. A detailed description of the retracted position
(separated position) and the developed position will be made hereinafter. In
Figures 137 and 129, for the sake of explanation, the portions other than the contacted portion 520c and the spacer restricting surface (spacer restriction
portion) 520d of the drive-side cartridge cover member 520 are omitted.
[0802] As described above, the developing unit 9 is supported so as to be rotatable about the swing axis K relative to the photosensitive drum 4 by fitting
the outer diameter portion of the cylindrical portion 533b of the development
cover member 533 into the supporting hole portion 520a of the drive-side
cartridge cover member 520. Further, the development cover member 533 is
provided with a cylindrical support portion 533c which projects in the
longitudinal direction along the swing axis K. Then, the outer peripheral surface
of the support portion 533c is fitted with the inner peripheral surface of the
supported hole 510a of the spacer 510, and the support portion 533c rotatably
supports the spacer 510. Here, the swing axis (rotation shaft) of the spacer 510 assembled to the development cover member 533 is referred to as a swing axis H.
The swing axis H is substantially parallel to the swing axis K.
[0803] Further, the development cover member 533 is provided with a retaining portion 533d which projects in the longitudinal direction along the
swing axis H. The retaining portion 533d can be elastically deformed in a direction away from the support portion 533c when the spacer is assembled to the
development cover member 533. As shown in Figure 137, the movement of the
spacer 510 assembled to the development cover member 533 in the swing axis H
direction is restricted by the retaining portion 533d being abutted by to the spacer
510. Further, even if the spacer 510 assembled to the development cover
member rotates and changes its attitude, the retaining portion 533d contacts the
spacer 510 to restrict the movement of the spacer 510.
[0804] As described above, the spacer 510 is rotatably supported by the development cover member of the developing unit 9 so as to be rotatable about
the swing axis H.
[0805] Further, in this embodiment, there is provided a tension spring 530 which is an elastic member as an urging member (holding portion urging
member) provided with a spacer portion urging portion (holding portion urging
portion) which urges the spacer 510 in the direction of arrow B1 in Figure 129.
The tension spring is a coil spring. The tension spring 530 is assembled to a
spring-hooked portion 533g provided on the development cover member 533 and
projecting in the swing axis K direction, and a spring-hooked portion 51Og of the
spacer assembled to the development cover member 533. The spring-hooked
portion 51Og corresponds to the point of action of the tension spring 530, and the
tension spring 530 moves the spacer (spacing holding member, holding member)
in the direction of arrow B1 in Figure 129 by applying a force to the spring
hooked portion 510g in the direction of the arrow F. Here, the direction of the arrow F in Figure 129 is substantially parallel to the line connecting the spring hooked portion 533g and the spring-hooked portion 510g. Then,asshownin part (a) of Figure 129, a first restricted surface 510h of the spacer 510 urged by the tension spring 530 is brought into engagement with a first restriction surface
533h provided on the development cover member 533. By this, the movement
of the spacer 510 in the direction of arrow BIin Figure 129 is restricted. That is,
the position of the spacer 510 relative to the development cover member 533 in
the rotational direction (arrow B1 direction) about the swing axis H is determined.
Here, the state in which the first restricted surface 51Oh and the first restriction
surface 533h are engaged with each other is referred to as a restriction position
(first position) of the spacer 510.
[0806] In this embodiment, the tension spring 530 is used as an example of the
urging member which urges the spacer 510 to the restriction position (first
position), but the present invention is not limited to this. For example, the
spacer 510 may be urged to the restriction position by using a torsion coil spring,
a leaf spring, or the like as an urging member. Further, the material of the
urging means may be metal, a mold or the like, which is elastic and can urge the
spacer 510.
[0807] In this manner, the developing unit 9 provided with the spacer 510 and
the tension spring 530 is coupled with the drum unit 8 by the drive-side cartridge
cover 520 as described above.
[0808] As shown in Figure 137, the force receiving portion 51Oe of the
assembled spacer 510 is on the same side as the side where the development
coupling member 74 or the photosensitive member coupling member 43 is placed
with respect to the direction of the rotation axis M2 of the developing roller 6.
[0809] Further, as shown in Figure 136, the drive-side cartridge cover 520
includes a contacted portion 520c. The contacted portion 520c is a ridge line portion formed at a corner where two surfaces perpendicular to the axis of the supporting hole 520a intersect, and is a ridge line portion extending substantially parallel to the axis of the supporting hole 520a. The ridge line portion as the contacted portion 520c may be a portion formed by chamfering, into a flat surface or a curved surface, a corner portion where two surfaces perpendicular to the axis of the supporting hole 520a intersect with each other. Further, as shown in
Figures 137 and 129, the contacted portion 520c is opposed to the contact surface
51Oc of the spacer 510 located at the restriction position so as to be contactable
thereto when the drive-side cartridge cover 520 is assembled to the developing
unit 9 and the drum unit 8. Further, as described above, the developing unit 9 is
rotatable about the swing axis K relative to the drum unit 8 and is subjected to the
urging force by the developing unit urging spring (not shown). Then, when the
contact surface 51c of the spacer 510 located at the restriction position and the
contacted portion 520c come into contact with each other, the position of the
developing unit 9 with respect to the drum unit 8 in the rotational direction about
the swing axis K is determined. When the position is determined in this manner,
the developing roller 6 and the photosensitive drum 4 of the developing unit 9 are
spaced by a gap T2. Here, the state in which the developing roller is spaced
from the photosensitive drum 4 by the gap T2 by the spacer 510 is referred to as
the retracted position (spacing position) of the developing unit 9 (state in part (a)
of Figure 129). When the developing unit 9 is in the retracted position
(separated position), it can be said that the developing frame is also in the
retracted position (spaced position).
[0810] Further, when the developing unit 9 is in the retracted position, the
force received by the contact surface 51Oc of the spacer 510 from the contacted
portion 520c and the force received by the inner peripheral surface of the
supported hole 51Oa from the supporting portion 533c are forces having vectors passing through the swing axis H (see part (a) of Figure 129) Furthermore, these forces are orientated in opposite directions, and therefore, these forces are balanced. Therefore, when the developing unit 9 is in the retracted position, the force received by the contact surface 51Oc from the first contacted portion 520c does not produce a moment around the swing axis H on the spacer 510. The contacted portion 520c may be formed so as to form an arc surface centered on the axis of the supporting hole 520a when the developing unit 9 is in the retracted position. Even with such a structure, when the developing unit 9 is in the retracted position, the force received by the contact surface 51Oc from the first contacted portion 520c does not produce a moment around the swing axis H on the spacer 510.
[0811] Further, as shown in the Figure 146 showing the positional relationship
between the photosensitive drum 4 and the developing roller 6, when the
developing unit 9 is placed at the retracted position, the axis M2 of the
developing unit 9 may not parallel with the axis M1 of the photosensitive drum 4.
Specifically, for example, the developing roller 6 may be partially spaced from
the photosensitive drum 4 in the direction of the axis M1 of the photosensitive
drum 4.
[0812] As described above, in the state that the spacer 510 is placed at the
restriction position and the developing unit 9 is placed at the retracted position,
when a force is applied to the force receiving portion 51Oe of the spacer 510 in
the direction of the arrow B2 in part (a) of Figure 129, the spacer 510 rotates
from the restriction position in the direction of the arrow B2 in part (a) of Figure
129. When the spacer 510 rotates in the direction of arrow B2, the contact
surface 51Oc separates from the contacted portion 520c, and the developing unit
can rotate in the direction of arrow V2 in part (a) of Figure 129 from the retracted
position. That is, the developing unit 9 rotates in the V2 direction from the retracted position, and the developing roller 6 included in the developing unit 9 becomes contactable to the photosensitive drum 4. Here, the position of the developing unit 9 in which the developing roller 6 and the photosensitive drum 4 contact with each other is referred to as a developing position (contact position)
(state of part (b) of Figure 129). When the developing unit 9 is in the developing position, it can be said that the developing frame is also in the
developing position (contact position).
[0813] In addition, the position in which the spacer 510 rotates from the restriction position in the direction of the arrow B2 in part (a) of Figure 129, the
contact surface 51Oc separates from the contacted portion 520c, and the
developing unit 9 is permitted to move from the retracted position (separated
position) to the developing position (the contact position) is referred to an
permission position (second position) (part (b) of Figure 129). When the
developing unit 9 is at the developing position, the restricted surface 510k of the
spacer 510 contacts the spacer restricting surface (spacer restriction portion) 520d of the drive-side cartridge cover 520, so that the spacer 510 is maintained in the
permission position (second position).
[0814] Further, the development cover member 533 is provided with a retracting force receiving portion (another force receiving portion, a second force
receiving portion, a separating force receiving portion) 533a projecting in the
radial direction of the cylindrical portion 533b. Similarly to the force receiving
portion 51Oe, the retracting force receiving portion 533a is also arranged on the
same side as the development coupling member 74 or the photosensitive member
coupling member 43 with respect to the direction of the rotation axis of the
developing roller 6. Since the development cover member 533 is fixed to the
developing unit 9, when the developing unit 9 is in the developing position and a
force is applied to the retracting force receiving portion 533a in the arrow W51 direction in part (b) of Figure 129, the developing unit is rotated about the moving axis K in the direction of the arrow VI in part (b) of Figure 129 to the retracted position. Here, in part (a) of Figure 129 and Figure 129 (b), the direction in which the retracting force receiving portion 533a moves when the developing unit 9 moves from the developing position to the retracting position is indicated by W51 direction, and the direction opposite to the arrow W51 direction is indicated by arrow W52 direction. The arrow W51 direction and the arrow W52 direction are substantially horizontal directions, and are substantially parallel with the direction in which at least two of the first to fourth process cartridges PY, PM, PC, and PK mounted on the image forming apparatus main assembly 502 are arranged. Further, the W51 direction and the W52 direction are substantially parallel to the moving direction of the separation control member 540 which will be described hereinafter.
[0815] The force receiving portion 51Oe included in the spacer 510 assembled
to the developing unit 9 is placed on the upstream side of the retracting force
receiving portion 533a in the direction of W51 in part (a) of Figure 129 and part
(b) of Figure 129. Further, as shown in part (a) of Figure 129 and Figure 129
(b), as viewed from the drive-side along the swing axis K, the force receiving
portion 51Oe and the retracting force receiving portion 533a are substantially
opposed to each other, and the force receiving portion 51Oe and the retracting
force receiving portion define a space Q surrounded by a two-dot chain line.
The space Q is a space opened in the direction of gravity when the process
cartridge P is mounted to the image forming apparatus main assembly 502.
Further, the space Q is formed both in a state in which the developing unit 9 is
placed in the retracted position and the spacer 510 is placed in the restriction
position (part (a) of Figure 129) and in a state in which the developing unit is
placed in the developing position and the spacer 510 is placed in the permission position (part (b) of Figure 129).
[Mounting to main assembly]
[0816] Next, referring to Figure 138, the operation when the process cartridge
P is mounted on the image forming apparatus main assembly 502 will be
described. Part (a) of Figure 138 is a view, as viewed from the drive-side, of a
state in which the process cartridge P is placed at the first inner position where
the photosensitive drum 4 and the transfer belt 112a are spaced from each other.
Further, part (b) of Figure 138 is a view, as viewed from the drive-side, of a state
in which the process cartridge P is placed at the second inner position where the
photosensitive drum 4 and the transfer belt 112a are in contact with each other.
For the sake of explanation, in part (a) of Figure 138 and part (b) of Figure 138,
parts are omitted except for the contacted portion 520c and the spacer restriction
surface 520d of the drive-side cartridge cover 520.
[0817] The image forming apparatus main assembly 502 includes the
separation control members (force applying member) 540 corresponding to
respective process cartridges P (PY, PM, PC, PK). The separation control
member 540 is disposed below the spacer 510 of the process cartridge P placed at
the first inner position and the second inner position (in the Z1 direction in Figure
138). The separation control member 540 includes a control portion (projecting
portion) 540a projecting toward the process cartridge P, and the control portion
540a has a first force application surface (retracting force applying portion,
separation force applying portion) 540b and a second force application surface
(force applying portion, contact force applying portion) 540c. The control
portion 540a of the separation control member 540 is provided below the lower
surface of the space Q of the process cartridge P placed at the first inner position
(in the ZI direction in Figure 138). Further, the separation control member 540
is placed so that a gap T5 is provided between the process cartridge P and the spacer 510 when the process cartridge P is at the first inner position (part (a) of
Figure 138). That is, as described above, the spacer 510 of the process cartridge
P inserted into the inside of the image forming apparatus main assembly 502 by
the tray 110 moving from the outer position to the first inner position enters into
the main assembly 502 without contacting the separation control member 540.
Then, when the process cartridge P is moved from the first inner position to the
second inner position by closing the front door 111 as described above, the
control portion 540a enters the space Q as shown in part (b) of Figure 138.
[0818] Further, Figure 142 shows a view of the process cartridge P set in the
image forming apparatus 502 as viewed in the direction of arrow J in part (b) of
Figure 138. For better illustration, Figure 142 shows the separation control
member 540 with omission of portions other than the control portion 540a. In
addition, some of the portions constituting the process cartridge P are omitted.
The retracting force receiving portion 533a is disposed downstream of the force
receiving portion 51Oe in the W51 direction (retraction direction, separation
direction), and a space Q is formed between the force receiving portion 51Oe and
the retracting force receiving portion 533a in the W51 direction. The W51
direction will be described in detail hereinafter.
[0819] As shown in Figure 142, the force receiving portion 51Oe of the spacer
510 and the retracting force receiving portion 533a of the development cover
member 533 are arranged so as to partially overlap each other in the direction
along the swing axis K of the developing unit 9 to define the space Q. Further,
when the process cartridge P is mounted at the second inner position (image
formable position) and the control portion 540a enters the space Q, the control portion 540a is arranged such that the force receiving unit 51Oe and the retracting
force receiving portion 533a overlap with each other in the direction along the
swingaxisK. Here, as shown in part (b) of Figure 138, the description will be made as to a state in which the process cartridge P is mounted at the second inner position of the image forming apparatus main assembly 502 and the developing unit 9 is in the retracted position. In this state, there is a gap T3 between the force receiving portion 51Oe and the second force application surface 540c, and the position of the separation control member 540 providing a gap T4 between the retracting force receiving portion 533a and the first force application surface
540b is called the home position.
[Contact operation]
[0820] Subsequently, referring to Figure 139, the description will be made as
to the operation of moving the developing unit 9 from the retracted position
(separation position) to the developing position (contact position) inside the
image forming apparatus main assembly 502. Figure 139 is a view of the
process cartridge P located at the second inner position inside the image forming
apparatus main assembly 502, as viewed from the drive-side. For better
illustration, the drive-side cartridge cover 520 is shown with omission of portions
other than the contacted portion 520c and the spacer restriction surface 520d.
Part (a) of Figure 139 shows a state in which the developing unit 9 is in the
retracted position (separated position) and the separation control member 540 is
in the home position. Part (b) of Figure 139 shows a state in which the
developing unit 9 is moving from the retracted position to the developing position.
Part (c) of Figure 139 shows a state in which the developing unit 9 is placed at
the developing position and the separation control member 540 is placed at the
first position. Part (d) of Figure 139 shows a state in which the developing unit
9 is placed at the developing position and the separation control member 540 is
placed at the home position. Here, as described above, at the home position of
the separation control member 540, there is a gap T3 between the second force
application surface 540c and the force receiving portion 51Oe of the process cartridge P mounted at the second inner position, and there is a gap T4 between the first force application surface 540b and the retracting force receiving portion
533a. The first position will be described hereinafter.
[0821] The development coupling member 74 receives a driving force from
the image forming apparatus main assembly 502 in the direction of the arrow V2
in part (a) of Figure 139, so that the developing roller 6 rotates. That is, the
developing unit 9 including the development coupling member 74 receives a
moment in the arrow V2 direction about the swing axis K, from the image
forming apparatus main assembly 502. When the developing unit 9 shown in
part (a) of Figure 139 is in the retracted position (separated position) and the
spacer 510 is in the restriction position (first position), even if the developing unit
9 receives this moment, the contact surface 51Oc of the spacer 510 contacts the
contacted portion 520c, the attitude of the developing unit 9 remains restricted to
the retracted position (separated position) (held at the retracted position). The
separation control member 540 of this embodiment is structured to be movable
from the home position in the arrow W52 direction in part (a) of Figure 139.
When the separation control member 540 moves in the W52 direction, the second
force application surface (contact force applying portion) 540c of the control
portion 540a and the force receiving portion (contact force receiving portion)
51Oe of the spacer 510 are brought into contact with each other, and the spacer
510 is moved in the direction B2 in part (a) of Figure 139. The spacer 510 that
rotates in this manner moves to the permission position (second position) where
the contact surface 51Oc and the contacted portion 520c are separated from each
other. Here, the position of the separation control member 540 which moves the
spacer 510 to the permission position shown in part (b) of Figure 139 is referred
to as a first position.
[0822] When the spacer 510 is moved to the permission position by the separation control member 540, the developing unit 9 rotates in the V2 direction by the moment received from the image forming apparatus main assembly 502 and the urging force of the developing unit urging spring 134, and moves to the developing position (contact position) where the developing roller 6 and the photosensitive drum 4 are in contact (part (c) of Figure 139) with each other.
Then, the separation control member 540 moves from the first position in the
W51 direction and returns to the home position (part (d) of Figure 139). The
spacer 510 is urged by the tension spring in the direction of the arrow B1
(direction from the permission position (second position) to the restriction
position (first position)) in the part (d) of Figure 12. However, by the restricted
surface 510k of the spacer 510 contacting the spacer restriction surface 520d of
the drive-side cartridge cover 520, the movement of the spacer 510 toward the
restriction position (first position) is restricted, and the spacer 510 is maintained
in the permission position (second position).
[0823] As shown in part (d) of Figure 139, also when the separation control
member 540 returns to the home position with the developing unit 9 in the
developing position and the spacer 510 in the permission position, the gap T3 is
formed between the force receiving portion 51Oe(contact force receiving portion)
of the spacer 510 and the second force application surface (contact force applying
portion) 540c of the separation control member 540. Similarly, the gap T4 is
formed between the retracting force receiving portion (separation force receiving
portion) 533a and the first force application surface (separation force applying
portion) 540b. That is, the separation control member 540 becomes in a non
contact state with the process cartridge P and is not subjected to a load.
[0824] By moving the separation control member 540 from the home position
to the first position in this manner, the spacer 510 is moved from the restriction
position to the permission position, and the developing unit 9 is moved from the retracted position to the development position in which the developing roller 9 and the photosensitive drum 4 contact with each other.
[0825] The force receiving portion 51Oe is a force for moving the spacer 510
from the restriction position (first position) to the permission position (second
position), it can be said that the force (contact force) for moving the developing
unit 9 and the developing frame from the retracted position (separation position)
to the developing position is received from the separation control member 540.
[0826] With the developing unit 9 in the contact position (development
position), the position of the developing unit 9 relative to the drum unit 8 is
determined by being urged in the V2 direction by the drive torque received from
the image forming apparatus main assembly 502 and the developing unit urging
spring 134 and by the developing roller 6 contacting the photosensitive drum 4.
Therefore, the photosensitive drum 4 can be said to be a positioning portion
(second positioning portion) for positioning the developing roller of the
developing unit 9 at the developing position. At this time, it can be said that the
developing unit 9 is stably held by the drum unit 8. At this time, the spacer
151R in the separation release position is not directly concerned in the
positioning of the developing unit 109. However, it can be said that the spacer
510 creates a situation in which the drum unit 8 can stably hold the developing
unit 9 at the contact position (development position) by moving from the
separation holding position to the separation release position.
[Separation operation]
[0827] Subsequently, the operation of moving the developing unit 9 from the
developing position to the retracting position will be described referring to Figure
140. Figure 140 is a view of the process cartridge P placed at the second inner
position inside the image forming apparatus main assembly 502, as viewed from
the drive-side, as in Figure 139. For better illustration, the drive-side cartridge cover 520 is with the omission of parts other than the contacted portion 520c and the spacer restriction surface 520d. Part (a) of Figure 140 shows a state in which the developing unit 9 is in the developing position and the separation control member 540 is in the home position. Part (b) of Figure 140 shows a state in which the developing unit 9 is moving from the developing position to the retracted position. Part (c) of Figure 140 shows a state in which the developing unit 9 is in the retracted position.
[0828] The separation control member 540 of this embodiment is structured to
be movable from the home position in the W51 direction in part (a) of Figure 140.
When the separation control member 540 moves in the W51 direction, the first
force application surface 540b and the retracting force receiving portion
(separation force receiving portion) 533a of the development cover member 533
come into contact with each other, and the retracting force receiving portion 533a
moves at least in the W51 direction, and therefore, the developing unit 9 rotates
in the direction of arrow VI in Figure 140. That is, the developing unit 9 moves
from the developing position toward the retracted position (separated position)
against the urging force of the developing unit urging spring 134. Thus, the
W51 direction is a direction in which the retracting force receiving portion 533a
at least moves by receiving a force from the first force application surface 540b in
order to move the developing unit 9 from the developing position to the retracting
position, and it can be called a retracting direction (separation direction). Then,
as the developing unit 9 rotates in the direction of the arrow VI in part (a) of
Figure 140, the restricted surface 510k of the spacer 510 and the spacer restriction
surface 520d of the drive-side cartridge cover 520 are separated from each other.
Therefore, the spacer 510 is rotated in the direction of the arrow B1 (direction
from the permission position to the restriction position) in part (a) of Figure 140
by the urging force of the tension spring 530. The spacer 510 rotates until the first restricted surface 51Oh comes into contact with the first restriction surface
533h of the development cover member 533, and moves to the restriction position
(first position). When the developing unit 9 is moved from the developing
position to the retracted position by the separation control member 540 and the
spacer 510 is placed at the restriction position (first position), the gap T5 is
formed between the contact surface 51Oc and the contacted surface 520c, as
shown in part (b) of Figure 140. Here, the position of the separation control
member 540 shown in part (b) of Figure 140 in which the developing unit 9 is
rotated from the developing position toward the retracted position and the spacer
510 can be moved to the restriction position is referred to as a second position.
[0829] Further, when the separation control member 540 moves from the
second position in the W52 direction W52 in part (b) of Figure 140 and returns to
the home position, the developing unit 9 rotates in the direction of the arrow V2
in Figure 140 by the moment in the arrow V2 direction shown in Figure 140 so
that the contact surface 51Oc and the contacted portion 520c come into contact
witheachother. At this time, the spacer 510 is still maintained in the restriction
position by the urging force of the tension spring 530. Therefore, the
developing unit 9 is in a state where the retracting position is restricted by the
spacer 510, and the developing roller 6 and the photosensitive drum 4 are spaced
by the gap T2 (part (c) of Figure 140). The moment in the V2 direction is
produced by the urging force of the developing unit urging spring 134 and the
driving force received by the development coupling member 74 from the image
forming apparatus main assembly 502. That is, the developing unit 9 is
restricted by the spacer 510 in the movement to the contact position against the
driving force received from the image forming apparatus main assembly 502 and
against the moment (urging force) in the arrow V2 direction by the urging of the
development pressure spring 134, and is maintained in the separation position.
[0830] As described above, It can be said that the retracting force receiving portion (separation force receiving portion) 533a receives, from the separation
control member 540, a force (retracting force, separation force) for moving the
spacer 510 from the permission position (second position) to the restriction
position (first position), for moving the developing unit 9 and the developing frame from the developing position to the retracting position (spaced position).
[0831] Further, as shown in part (c) of Figure 140, when the separation control member 540 returns to the home position while the developing unit 9 is in the
retracted position and the spacer 510 is in the restriction position, the gap T3 is
formed between the force receiving portion (contact force receiving portion)510e
of the spacer 510 and the second force application surface (contact force applying
portion) 540c of the separation control member 540. Similarly, the gap T4 is
formed between the retracting force receiving portion (separating force receiving
portion) 533a and the first force application surface (spacing force applying
portion) 540b. That is, the separation control member 540 becomes in a non contact state relative to the process cartridge P and is not subjected to a load.
[0832] As described above, in this embodiment, the spacer 510 moves from the permission position to the restriction position by moving the separation
control member 540 from the home position to the second position. Then, by
the separation control member 540 returning from the second position to the
home position, the developing unit 9 becomes in a state of maintaining the
retracted position by the spacer 510. That is, in this embodiment, the spacer 510
is in the restriction position, and the contact surface 51Oc and the contacted
portion 520c are in contact with each other even when the retracting force
receiving portion (separation force receiving portion) 533a and the first force
application surface (separating force applying portion) 540b are separated from
each other. Therefore, it is possible to restrict the developing unit 9 in moving to the developing position and maintain it in the retracted position (separated position).
[0833] In order to perform the above-mentioned contact operation and
separation operation, the width between the force receiving portion 51Oe and the
retracting force receiving portion 533a in the W51 direction or the W52 direction
when the developing unit 9 is in the separated position is preferably 3.5 mm or
more, and is further preferably 18.5 mm or less, even further preferably 10 mm or
less. With such a dimensional relationship, it is possible to perform an
appropriate contact operation and separation operation.
[0834] With the developing unit 9 in the separated position (retracted position),
the position of the developing unit 9 relative to the drum unit 8 is determined by
being urged in the V2 direction by the driving torque received from the image
forming apparatus main assembly 502 and the developing unit urging spring 134,
by the contact between the supported portion 51Oa and the supporting portion
533c and by the contact between the contact portion 51Oc and the contacted
portion 520c. Therefore, the contacted portion 520c can be said to be a
positioning portion (first positioning portion) for positioning the developing unit
9 when the photosensitive drum 4 is in the spaced position (retracted position).
At this time, it can be said that the developing unit 9 is stably held by the drum
unit 8. Further, it can be said that the spacer 510 at the restriction position (first
position) creates a situation in which the drum unit 8 can stably hold the
developing unit 9 at the spaced position (retracted position).
[0835] In this embodiment, by moving the separation control member 540
between the home position, the first position, and the second position in one
direction (W51, W52), the contact/separation state between the developing roller
6 and the photosensitive drum 4 can be controlled. Therefore, the developing
roller 6 can be brought into contact with the photosensitive drum 4 only when the image is formed, and the developing roller 6 can be maintained in a state of being spaced from the photosensitive drum 4 when the image is not formed. Therefore, even if the image is left for a long time without forming an image, the developing roller 6 and the photosensitive drum 4 are not deformed, and therefore, a stable image forming operation can be accomplished.
[0836] Further, in the process cartridge P, as viewed along the rotation axis M1 of the photosensitive drum 4 or the rotation axis M2 of the developing roller
6, the retracting force receiving portion (separation force receiving portion) 533a
and the force receiving portion (contact force receiving portion) 51Oe are opposed
to each other with a space formed therebetween. That is, in the W51 direction
(or W52 direction), the retracting force receiving portion (separation force
receiving portion) 533a and the force receiving portion (contact force receiving
portion) 510e are arranged so as to form a gap therebetween. Further, regardless
of whether the developing unit 9 is in the developing position or the retracting
position, the retracting force receiving portion (separation force receiving portion) 533a is closer to the rotation axis M1 of the photosensitive drum 4 than
the force receiving portion (contact force receiving portion) 51Oe, as viewed
along the rotation axis M1 of the photosensitive drum 4 or the rotation axis M2 of
the developing roller 6.
[0837] With such an arrangement, in the separation control member 540, one
control portion 540a which is one projection projecting toward the process
cartridge P is enough, the control portion 540a having the first force application
surface (separation force applying portion) 540b and the second force application
surface (contact force applying portion) 540c. For this reason, the stiffness
required for the first force application surface 540b and the second force
application surface 540c to act on the process cartridge P can be provided in one
place of the control portion 540a, and the entire separation control member 540 or the control can be provided can be downsized. By this, the apparatus main assembly 502 can be downsized. Further, the cost can be reduced by reducing the volume of the separation control member 540 itself.
[0838] In addition, when the separation control member 540 is in the home
position, no load is applied to the control portion 540a from the process cartridge
P, so that the rigidity required for the mechanism for operating the separation
control member 540 and the separation control member 540 can be reduced, and
therefore, the downsizing can be accomplished correspondingly. Further, the
load on the sliding portion of the mechanism for operating the separation control
member 540 is also reduced, and therefore, wearing of the sliding portion and
generation of abnormal noise can be suppressed.
[0839] Further, the first force application surface 540b of the control portion
540a directly presses the retracting force receiving portion 533a of the developing
member b-member 533 fixed to the developing unit 9, so that the developing unit
9 is moved from the developing position to the retracting position. Therefore,
the sliding friction at the time when moving the developing unit 9 from the
developing position to the retracted position can be minimized, and therefore, the
load applied to the control portion 540a can be further reduced.
[0840] Further, conventionally, the developing unit has a structure in which
the developing unit is positioned at the retracted position by contact between the
developing unit and the separation control member of the apparatus main
assembly, and a positional error between the developing unit and the separation
control member at the retracted position occurs by a position error due to a
component tolerance or the like. Then, the position error of the retracted
position causes a variation in the amount of separation between the developing
roller and the photosensitive drum. In preparation for such a positional error in
the retracted position of the developing unit, it is necessary to design the spacing amount so that the developing roller and the photosensitive drum can be sufficiently spaced even if the positional error occurs. Further, it is necessary to design a large gap or the like between the developing unit at the retracted position and another member in preparation for the positional error of the retracted position.
[0841] On the other hand, in this embodiment, the retracted position of the
developing unit 9 is determined by the spacer 510, and therefore, the positional
error between the separation control member 540 and the developing unit 9 is not
influential. Therefore, since the position error at the retracted position of the
developing unit 9 is reduced, the variation in the spacing amount between the
developing roller 6 and the photosensitive drum 4 is also reduced
correspondingly, and the spacing amount can be designed to be smaller. Since
the amount of spacing can be reduced, the amount of movement of the
developing unit 9 from the developing position to the retracted position is also
small, and the process cartridge can be downsized. Further, the space for
placing the process cartridge P in the main assembly can be reduced, and the
image forming apparatus can be downsized. Alternatively, the space of the
developing material accommodating portion 29 of the developing unit 9 can be
increased, and the large-capacity process cartridge P can be placed in the image
forming apparatus main assembly 502. Further, the gap between the developing
unit 9 at the retracted position and another member (the drum unit 8, for example)
can be designed to be smaller as the positional error at the retracted position is
reduced.
[0842] Further, the spacer 510 is disposed on the same side with respect to the
rotation axis direction of the development coupling 74 and the developing roller 6.
By this, in the case that the developing unit 9 is restricted to the retracted position,
the amount of deformation of the developing unit 9 by the moment received from the image forming apparatus main assembly 502 when the driving force is transmitted to the development coupling 74 can be reduced.
[0843] Further, the force receiving portion 51Oe of the spacer 510 is disposed
on the same side as the photosensitive member coupling member 43 with respect
to the rotation axis of the photosensitive member coupling member 43. By this,
the timing at which the spacer 510 is moved from the regulated position to the
permission position and the developing roller 6 is brought into contact with the
photosensitive drum 4 which is rotating can be performed more accurately.
[0844] In this embodiment, the urging force of the tension spring 530 is used
as a means for moving the spacer 510 from the permission position to the
restriction position, but this disclosure is not limited to such an example. In
another embodiment, as shown in Figure 144, there is no spring 530 provided
which urges the spacer 510 from the permission position towards the restriction
position. In this embodiment, a spacer 710 moves from the permission position
to the restriction position by rotation due to its own weight. When the
developing unit 9 is moved from the developing position to the retracted position,
the spacer 710 of Figure 144 rotates in the direction B Iin part (a) of Figure 144
due to its own weight, and moves from the permission position to the regulated
position.
[Arrangement details - Part 1]
[0845] Subsequently, referring to Figure 141, the arrangement of the spacer
510 will be described in detail. Figure 141 is a view of the process cartridge P
as viewed from the drive-side along the direction of the rotation axis of the
photosensitive drum 4. The developing unit 9 is placed at the retracted position,
and the spacer 510 is placed at the restriction position. Further, for better
illustration, the drive-side cartridge cover 520 is shown by omitting portions other
than the contacted portion 520c and the spacer restriction surface 520d.
[0846] As shown in Figure 141, the rotation axis (rotation center) of the
photosensitive drum 4 is M1, the rotation axis (rotation center) of the developing
roller 6 is M2, and the straight line connecting the rotation axis Mi of the
photosensitive drum 4 the axis (center of rotation) K of the development coupling
member 74is line NI. In this embodiment, the rotation axis of the
photosensitive member coupling member 43 is coaxial with the rotation axis MI.
When the region is divided with the line Ni as the boundary, the rotation axis M2
of the developing roller 6 and the force receiving portion 51Oe are in the same
side with respect to the line Ni as the boundary. Further, the distance between
the rotating axis K of the development coupling member 74 and the rotating axis
M2 of the developing roller 6 is e, and the distance between the rotating axis K
of the development coupling member 74 and the force receiving portion 51Oe is
e2. In this case, the force receiving portion 510e is disposed so that the distance
e2 is larger than the distance el.
[0847] By disposing the force receiving portion 51Oe in this manner, the force,
received from the image forming apparatus main assembly 502 by the force
receiving portion 51Oe, for moving the spacer 510 from the restriction position to
the permission position can be converted into a force for bringing the developing
roller 6 into contact with the photosensitive drum 4. That is, when the spacer
510 is moved from the restriction position to the permission position, the
developing roller 6 can be brought into contact with the photosensitive drum 4
more quickly, so that the timing at which the developing roller 6 is brought into
contact with the rotating photosensitive drum 4 can be controlled with higher
accuracy.
[Arrangement details - Part 2]
[0848] Subsequently, referring to Figure 143, the arrangement of the spacer
510 will be described in detail. Figure 143 is a view of the process cartridge P as viewed from the drive-side along the direction of the rotation axis M1 of the photosensitive drum 4 or the rotation axis M2 of the developing roller. The developing unit 9 is placed at the developing position, and the spacer 510 is placed at the permission position. Further, for better illustration, the drive-side cartridge cover 520 is shown by omitting portions other than the contacted portion 520c and the spacer restriction surface 520d.
[0849] As shown in Figure 143, the straight line connecting the rotation axis M1 of the photosensitive drum 4 and the rotation axis M2 of the developing roller
6 is line N2. When the region is divided by the line N2 (the upper side is a
region AUl and the lower side is a region AD1), at least a part of the force
receiving portion 51Oe and at least a part of the retracting force receiving portion
533a are disposed in the region AD1 which is opposite to the region in which the
rotation axis K of the development coupling member 74 exists. That is, at least
a part of the force receiving portion 51Oe and at least a part of the retracting force
receiving portion 533a are disposed in the region AD Iwhich is opposite to the region AUl in which the rotation center K of the development coupling member
74 is provided. As described in the Embodiment 1, in the region AUl, the
structure for movably supporting the developing unit 9 relative to the drum unit 8
and a driving member for driving the members provided in the developing unit 9
are provided. Therefore, it is possible to provide an efficient layout that avoids
interference between the members by disposing at least a part of the force
receiving portion 51Oe and at least a part of the retracting force receiving portion
533a in the region ADI rather than in the region AUl. This is contributableto
downsizing of the process cartridge 100 and the image forming apparatus M.
[0850] Further, a line perpendicular to the line N2 and passing through the
contact point between the developing roller 6 and the photosensitive drum 4 is a
line N3. When the region is divided by the line N3, at least a part of the force receiving portion 51Oe and at least a part of the retracting force receiving portion
533a are disposed in the region which is opposite to the region in which the
rotation axis M1 of the photosensitive drum 4 exists, with respect to the line N3
as a boundary.
[0851] In the foregoing description, when the region is divided by the straight
line N2 as viewed in the direction along the rotation axis M2, the regions AUl
and AD Iare the regions where the rotation axis K or the development coupling
32 is disposed, and the regions where the development coupling is not arranged,
respectively. However, as another definition, when the region is divided by the
straight line N2 as viewed in the direction along the rotation axis M2, the regions
AUl and the region AD Imay be defined as region where the charging roller 5 or
the rotation axis M5 of the charging roller 5 or is disposed, and the region where
it is not disposed.
[0852] As yet another definition, as the region is divided by the straight line
N2 as viewed in the direction along the rotation axis M2, the region AUl and the
region AD Imay be defined as a region in which the developing blade 30, the
proximity point 30d (see Figure 240), and the stirring member 29a (Figure 240)
are provided and the region in which it is not provided. The proximity point 30d
is the position closest to the surface of the developing roller 6 of the developing
blade 30.
[0853] In an ordinary electrophotographic cartridge, particularly a cartridge
usable with an in-line layout image forming apparatus, it is relatively difficult to
arrange other members of the cartridge in the region AD1. Further, if the force
receiving portion 51Oe and the retracting force receiving portion 533a are
arranged in the region AD1, the apparatus main assembly 502 also has the
following advantage. That is, the separation control member 540 of the
apparatus main assembly 502 is arranged under the cartridge P and moved in the substantially horizontal direction (in this embodiment, the W51 and W52 directions and the arrangement direction of the photosensitive drum 4 or the cartridge P) to press the force receiving portion 51Oe and the retracting force receiving portion 533a. With such a structure, the separation control member
540 and the drive mechanism therefor can be of a relatively simple and small size structure. This is particularly remarkable in the in-line layout image forming
apparatus. In this manner, disposing the force receiving portion 510e and the
retracting force receiving portion 533a in the region AD Ican be expected to
contribute to the downsizing and cost reduction of the apparatus main assembly
502.
[0854] The arrangement of the force receiving portion 51Oe and the retracting force receiving portion 533a has been described referring to Figure 143 showing
the cartridge P in the contact state, but the same relationship also applies to the
cartridge P in the separated state as will be apparent from other Figures.
Although Figure shows the cartridge P in the contact state, the arrangement of the force receiving portion 51Oe and the retracting force receiving portion 533a is the
same as that described above.
[0855] Further, assuming that the direction perpendicular to the straight line N2 is the VD1 direction, the projecting portion 510d provided with the force
receiving portion 51Oe and the retracting force receiving portion 533a in the form
of the projecting portion are disposed at positions such that they are projected
from the developing unit 9 at least in the direction VD1, when the movable
member 152R is in the operating position. Therefore, the force receiving
portion 51Oe and the retracting force receiving portion 533a can be arranged so
that the first force application surface 540b of the separation control member 540
is contactable to the retracting force receiving portion 533a and so that the second
force application surface 540c is contactable to the force receiving portion 51Oe.
The same applies to the structure on the non-drive-side.
[0856] Further, the diameter of the developing roller 6 of this structure is
smaller than the diameter of the photosensitive drum 4. By arranging the force
receiving portion 51e in this manner, it can be disposed in a small space so that
the drive transmitting portion (not shown) and the photosensitive drum 4
including the gear trains and the like for transmitting the driving force from the
development coupling member 74 to the developing roller 6 are avoided. By
this, the process car cartridge P can be downsized.
[0857] In the contact operation shown in part (b) of Figure 139, the force
receiving portion 51Oe receives a force (external force) from the second force
application surface 540c of the separation control member 540 in a region
opposite to the region in which the rotation axis M1 of the photosensitive drum 4
exists, with the line N3 as a boundary. The direction of the force received by
the force receiving portion 51Oe from the second force application surface 540c
(W52 direction) is the direction in which the developing unit 9 moves from the
retracted position to the developing position. Therefore, the developing unit 9
can be moved more reliably from the retracted position to the developing position
by the force received by the force receiving portion 51Oe from the second force
application surface 540c.
[Arrangement details - Part 3]
[0858] Referring to Figures 240 and 241, a concept similar to the concept of
arranging at least a part of each of the force receiving portion 51Oe and the
retracting force receiving portion 533a in the region ADI as described above will
be described.
[0859] Figure 240 and 241 are illustrations of the process cartridge P as
viewed from the drive-side along the rotation axis Ml of the developing unit 9,
the rotation axis K, or the rotation axis M2, Figure shows a separated state, and
Figure 241 shows a contact state. Since the arrangement of the spacer 510
described in the following is almost the same in the contact state and the
separation state, only the separation state will be described referring to Figure
240, and the description in the contact state will be omitted.
[0860] The rotation axis of the toner feeding roller (developer supply member)
107 is a rotation axis (rotation center) M6. Further, the process cartridge 100
includes a stirring member 108 which rotates and stirs the developer contained in
the developing unit 109, and the rotation axis thereof is a rotation axis (rotation
center) M7.
[0861] In Figure 236, the intersection of the straight line N10 connecting the
rotation axis M5 and the rotation axis M5 and the surface of the photosensitive
drum 104, whichever is more remote from the rotation axis M5, is an intersection
MX1. The tangent line to the surface of the photosensitive drum 104 passing
through the intersection MX1 is a tangent line (predetermined tangent line) NI1.
The region is divided by the tangent line Ni las a boundary, and the region
containing the rotation axis M1, the charging roller 105, the rotation axis M5, the
development coupling portion 132a, the rotation axis K, the developing blade 130,
the proximity point 130d, the toner feeding roller 107, the rotation axis M6, and
the stirring member 129a, the rotation axis M7, or the pressed surface 152Rf is
arranged is a region AU2, and the region where they do not exist is a region
(predetermined region) AD2. Further, the regions AU2 and AD2 may be
defined in another way as follows. That is, assuming that the direction parallel
to the direction from the rotation axis M5 to the rotation axis M and orientating
the same is VD10, the most downstream portion of the photosensitive drum 104
with respect to the direction VD10 is the intersection MX1. Then, with respect
to the direction VD10, the region on the upstream side of the most downstream
portion MX1 is the region AU2, and the region on the downstream side is the region (predetermined region) AD2. Regardless of such expression, the defined regions AU2 and AD2 are the same.
[0862] Then, at least a part of each force receiving portion 152Rk and 152Rn
is disposed in the region AD2. As described above, arranging at least a part of
each of the force receiving portions 152Rk and 152Rn in the region AD2 can be
expected to contribute to the downsizing and cost reduction of the process
cartridge 100 and the apparatus main assembly 170. This is for the same reason
as when at least a part of each of the force receiving portions 152Rk and 152Rn is
arranged in the region AD1. The same applies to the structure on the non-drive
side.
[0863] Further, the movable member 152R and the force receiving portions
152Rk and 152Rn are displaced at least in the VD10 direction by moving in the
ZA direction and the opposite direction. By such displacement in the VD10
direction, when the process cartridge is inserted into or removed from the
apparatus main assembly 170, it is possible to avoid that the movable member
152R and the force receiving portions 152Rk and 152Rn interfere with the
separation control member 196R with the result of incapability of insertion and
removal of the process cartridge 100. The same applies to the structure on the
non-drive-side.
[0864] Further, let the direction perpendicular to the straight line Ni1 be
VD10, the projecting portion 510d provided with the force receiving portion 510e
and the retracting force receiving portion 533a in the form of the projecting
portion are disposed at a position such that they are projected from the
developing unit 9 at least in the VD10 direction, when the movable member 152R
is in the operating position. Therefore, the force receiving portion 510e and the
retracting force receiving portion 533a can be disposed so that the first force
application surface 540b of the separation control member 540 is contactable with the retracting force apply surface 533a and so that the second force application surface 540c is contactable with the force receiving portion 51Oe.
The same applies to the structure on the non-drive-side.
[0865] The arrangement relationship of each force receiving portion described
above has the same relationship in all the examples described in the following.
<Another Example 1 of Embodiment 9>
[0866] In this embodiment, the spacer 510 is supported by the developing unit
9, but this disclosure is not limited to such an example. As another example 1,
as shown in Figure 145, the spacer 910 is supported by providing the drive-side
cartridge cover member 920 of the drum unit 8 with a boss (support portion) 920a
and inserting it into the hole (supported portion) of the spacer 910. Inthis
example, when the spacer 910 is in the restriction position (first position), the
contact portion 910c of the spacer 910 can contact the contacted portion provided
on the developing frame (second frame) of the developing unit (second unit) 9
(notshown). When the contact portion 910c and the contacted portion (not
shown) are in contact with each other, the developing unit 9 is positioned with the
attitude in which the developing roller 6 and the photosensitive drum 4 are
separated by a gap T2 (the developing unit 9 is in the retracted position). When
the separation control member 540 moves in the W52 direction from the state
where the developing unit 9 is in the retracted position (separated position), the
second force application surface 540c of the control portion 540a and the force
receiving portion 910e of the spacer 910 brought into contact with each other, so
that the spacer 510 rotates in the direction of arrow B2 in Figure 145. The
spacer 910 which rotates in this manner moves to a permission position (second
position) where the contact surface 91Oc and the contacted portion (not shown) of
the developing unit 9 are spaced from each other. When the spacer 910 is
moved to the permission position by the separation control member 540, the developing unit 9 is rotated by the moment received from the image forming apparatus main assembly 502 and the urging force of the developing unit urging spring 134, so that the developing unit 9 is moved to the developing position
(contact position) in which the developing roller 6 and the photosensitive drum 4
are in contact with each other
[0867] Further, the developing unit 9 in said another example 1 has the same
structure as in embodiment 1 shown in Figure 129 and so on, except for the
structure of the spacer 910 and the structures contacting it, for example, the
developing unit 9 includes the retracting force receiving portion 533a at the same
position as that of the retracting force receiving portion 533a of embodiment 1
shown in Figure 129 and so on.
[0868] Therefore, also in said another example 1, the straight line connecting
the rotation axis M1 of the photosensitive drum 4 and the rotation axis M2 of the
developing roller 6 is the line N2. When the region is divided by the line N2, at
least a part of the force receiving portion 91Oe and at least a part of the retracting
force receiving portion 533a are disposed in the region opposite to the region
having the rotation axis K of the development coupling member 74 with the line
N2 as the boundary. Further, a line perpendicular to the line N2 and passing
through the contact point between the developing roller 6 and the photosensitive
drum 4 is the line N3. When the region is divided by the line N3, at least a part
of the force receiving portion 910e and at least a part of the retracting force
receiving portion 533a are disposed in the region opposite to region having the
rotation axis M1 of the photosensitive drum 4 with the line N3 as a boundary.
<Another Example 2 of Embodiment 9>
[0869] In Embodiment 9, the swing axis of the developing unit 9 and the
rotation axis K of the development coupling member 74 are arranged coaxially,
but the present invention is not limited to such an example. As another Example
2, as shown in Figure 147, a supported hole 1333f may be provided in the
development cover member 1333, a supporting portion 1315b may be provided
on the drum frame 1315, the developing unit 9 may be made rotatable relative to
the drum unit about the supporting portion 1315b. The engaging portion 74a is
engageable with the main assembly side coupling member (not shown) of the
development coupling member 74. In this example, the engaging portion 74a is
provided with an axis eccentricity mechanism (Oldham coupling mechanism) for
permitting axis eccentricity toward a circumference of a circle having a center on
the support portion 1315b, relative to the other portion of the developing unit 9
(particularly the portion arranged on the downstream side in the drive
transmission path) by this, the engagement between the development coupling
member 74 and the main assembly side coupling member can be maintained
regardless of whether the developing unit 9 is in the retracted position or the
developing position.
[0870] Further, in place of the above-mentioned axis eccentricity mechanism
(Oldham joint mechanism), the structure may be the one with which the engaging
portion 74a of the development coupling member 74 allows the axis eccentricity
with respect to the main assembly side coupling member and the driving force is
transmitted at that time at the time when the axis eccentricity is eliminated
(coaxial state is established). Alternatively, a mechanism may be employed in
which when the engaging portion 74a is deviated with respect to the main
assembly side coupling member, at least one of the engaging portion 74a and the
main assembly side coupling member retracts in the axial direction with respect
to the other, and when the axial deviation is eliminated (coaxial state is
reestablished), the retraction is eliminated.
<Another Example 3 of Embodiment 9>
[0871] In the Embodiment 9 described above, the developing unit 9 swings about the swing axis K with respect to the drum unit 8 to move between the developing position (contact position) and the retracted position (separation position). However, the movement of the developing unit 9 between the developing position and the retracted position is not limited to swinging or rotating with respect to the drum unit 8. That is, in Embodiment 9, the developing unit 9 moves in a predetermined direction with respect to the drum unit 8 (, for example, linear movement), by which the developing unit 9 moves between the development position and the retracted position, in modified example 3. Specifically, as shown in Figure 148, it is possible that the supporting hole 1320a of the drive-side cartridge cover member 1320 has an oblong round hole shape with longitudinal direction thereof being the X1 direction (or X2 direction), so that the developing unit 9 is translated in the directions indicated by arrows X1 and X2 in Figure 33, by which it is moved between the development position (contact position) and the retracted position
(separation). Also in this modified example, as in alternative example 2 of the
Embodiment 9, the engaging portion 74a includes an axis eccentricity mechanism
(Oldham joint mechanism) which allows axis eccentricity in in the X2 direction
(or the X1 direction) direction relative to the other portion of the developing unit
(particularly the portion on the downstream side in the drive transmission path).
[0872] Further, in place of the above-mentioned axis eccentricity mechanism
(Oldham joint mechanism), such a structure may be such that while the engaging
portion 74a of the development coupling member 74 permits the axial
eccentricity relative to the main assembly side coupling member, the driving
force is transmitted at that time when the axis eccentricity is eliminated (becomes
coaxial). Alternatively, a mechanism may be provided so that in the case that
the engaging portion 74a is deviated relative to the main assembly side coupling
member, at least one of the engaging portion 74a and the main assembly side coupling member retracts in the axial direction relative to the other, and when the eccentricity is eliminated (when they become coaxial), the retraction is released.
<Embodiment 10>
[0873] Referring to Figure 149, the process cartridge and the image forming apparatus according to Embodiment 10 of the present disclosure will be described.
Members having the same functions or structures as in Embodiment 9 are
assigned by the same reference numerals, and detailed description thereof will be
omitted. The process cartridge of this embodiment differs from that of
Embodiment 9 only in the structure of the spacer and its surroundings, and the
other portions are the same. The image forming apparatus is also the same as
that of Embodiment 9.
[0874] In this embodiment, the spacer 610 is supported by the development cover member 533 as in Embodiment 9. On the other hand, the spacer 610
includes not only the force receiving portion (contact force receiving portion) 610e but also includes the retracting force receiving portion (separation force
receiving portion) 610m as another force receiving portion which receives the
force from the first force application surface 540b. Figure 149 is a view of the
process cartridge P placed at the second inner position inside the image forming
apparatus main assembly 502, as viewed from the drive-side. For better
illustration, the drive-side cartridge cover 520 is shown by omitting portions other than the contacted portion 520c and the spacer restriction surface 520d. Part (a)
of Figure 149 shows a state in which the developing unit 9 is in the developing
position and the separation control member 540 is in the home position. Part (b)
of Figure 149 shows a state in which the developing unit 9 is in the process of
moving from the developing position to the retracted position. Part (c) of Figure
149 shows a state in which the developing unit 9 is in the retracted position.
[0875] The separation control member 540 is structured to be movable from
the home position in the arrow W51 direction in part (a) of Figure 149. When
the separation control member 540 moves in the W51 direction, the first force
application surface 540b and the retracting force receiving portion 610m of the
spacer 610 are brought into contact with each other, and the spacer 610 rotates in
the direction of the arrow B Iin part (a) of Figure 149. During this rotation, the
spacer 610 remains in contact with the spacer restriction surface 520d or the
contacted portion 520c. Therefore, as the spacer 610 rotates, the distance
between the spacer restricting surface 520d of the spacer 610 or the contact
portion with the contacted portion 520c and the swing axis H of the spacer 610
increases. Therefore, the developing unit 9 rotates in the direction of arrow VI
in Figure 149, and the developing unit 9 moves from the developing position to
the retracted position. Further, as the developing unit 9 rotates in the direction
of the arrow V Iin part (a) of Figure 149, the spacer 610 separates from the
spacer restriction surface 520d and the contacted portion 520c of the drive-side
cartridge cover 520, and the spacer 610 is further rotates in the direction of the
arrow B Iin shown in part (a) of Figure 149. The spacer 610 rotates until the
first restricted surface 61Oh comes into contact with the first restriction surface
533h of the development cover member 533, and reaches the restriction position.
After the spacer reaches the restriction position, the first restricted surface 61Oh
presses the first restriction surface 533h, so that the developing unit 9 rotates in
the direction of arrow VI in Figure 149. Then, after the separation control
member 540 moves to the second position, when it moves in the W52 direction in
part (b) of Figure 149 and returns to the home position, the developing unit 9
maintains the separation position as in embodiment 9 by the spacer 610 placed at
the restriction position.
[0876] Further, similarly to Embodiment 9, the straight line connecting the rotation axis M1 of the photosensitive drum 4 and the rotation axis of the developing roller 6 to M2 is a line N2. When the region is divided by the line N2, at least a part of the force receiving portion 610e and at least a part of the retracting force receiving portion 61Om are disposed in the region opposite to the region including the rotation axis K of the development coupling member 74 with the line N2 as the boundary. Further, a line perpendicular to the line N2 and passing through the contact point between the developing roller 6 and the photosensitive drum 4 is the line N3. When the region is divided by the line N3, at least a part of the force receiving portion 610e and at least a part of the retracting force receiving portion 61Om are disposed in the region opposite to the region having the rotation axis M1 of the photosensitive drum 4 with the line N3 as a boundary.
[0877] According to the structure of this embodiment described above, the same effects as those of the first and Embodiment 9s can be provided.
[0878] Further, in this embodiment, since the force receiving portion 610e and the retracting force receiving portion 610m are the integral spacer 610, the
distance between the force receiving portion 610e and the retracting force
receiving portion 610m can be disposed more accurately. Therefore,the
switching timing between the developing position and the retracting position of
the developing unit 9 can be made accurate.
[0879] Further, in this embodiment, the spacer 610 can be moved from the permitting position to the restriction position by receiving a force for the
retracting force receiving portion 61Om to rotate in the direction of arrow B1
from the first force application surface 540b, the tension spring 530 used in
embodiment 9 is not provided. Therefore, in the structure of this embodiment, the cost of the process cartridge can be reduced or the size can be reduced by the
amount occupied by the tension spring 530 in the structure as compared with the
Embodiment 9. However, similarly to the tension spring 530, a spring which is
an elastic member may be provided as a developing frame urging member which
urges the spacer 610 to rotate in the direction of arrow B1.
<Embodiment 11>
[0880] Referring to Figures and 151, an image forming apparatus according to
the Embodiment 11 of the present disclosure will be described. Members
including the same structure and function as in the Embodiment 9 are designated
by the same reference numerals, and detailed description thereof will be omitted.
[0881] The process cartridge P of the Embodiment 9 is provided with two
input portions including the development coupling member 74 which receives a
driving force from the image forming apparatus main assembly 502 and transmits
the driving force to the developing roller and the photosensitive member coupling
member 43 which transmits the driving force to the photosensitive drum 4. In
this embodiment, one input portion receives a driving force from the image
forming apparatus main assembly 502, and the driving force is branched in the
process cartridge P to rotate the photosensitive drum 4 and the developing roller 6.
Other than these points, the process cartridge and image forming apparatus of this
embodiment are the same as those of Embodiment 9. In this embodiment, the
example 1 and example 2 will be described.
[Example 1]
[0882] Figure 150 is a perspective view of the structure of Example 1 of this
Embodiment in which the developing unit 9 is provided with a coupling member
174. For better illustration, some members are omitted. The coupling member
174 is arranged on the drive-side and engages with a coupling (not shown) of the
image forming apparatus main assembly 502 to receive a driving force. The
coupling member 174 is rotatably supported by a development cover member 533
(a portion of the developing frame) similarly to the development coupling
member of the Embodiment 9. The coupling member 174 transmits the driving
force to the gear 801, the gear 801 transmits the driving force to the gear 802, and
the gear 802 transmits the driving force to the developing roller 6. Further, the
developing roller 6 transmits the driving force to the gear 803, and the gear 803
transmits the driving force to the gear 804. The gear 804 transmits a driving
force to the photosensitive drum 4, by which the photosensitive drum 4 rotates.
That is, the driving force received from the image forming apparatus main
assembly 502 by the coupling member 174 is branched in the process cartridge to
rotate the developing roller 6 and the photosensitive drum 4. Therefore, the
coupling member 174 is a coupling member for receiving the driving force for
rotationally driving the photosensitive drum 4.
[0883] As shown in Figure 150, the spacer 510 and the force receiving portion
51e thereof is provided on the same side as the side on which the coupling
member 174 is disposed with respect to the rotation axis direction of the
developing roller 6. By arranging the spacer 510 and the force receiving portion
51Oe of the spacer 510 in this manner, the spacer 510 receives the moment
produced by the driving force received by the coupling member 174 from the
image forming apparatus main assembly 502, in the neighborhood. Therefore,
the deformation of the developing unit 9 can be made smaller, and the distance
between the developing roller 6 and the photosensitive drum 4 can be controlled
with high accuracy.
[Example 2]
[0884] Figure 151 is a perspective view of the structure of the Example 2 in
which the drum unit 8 is provided with the coupling member 143. For better
illustration, some members are omitted. The coupling member 143 is disposed
on the drive-side (fixed to the end of the photosensitive drum on the drive-side) and receives a driving force from the image forming apparatus main assembly
502. The coupling member 143 is rotatably supported by a non-drive-side
cartridge cover member 521 (a portion of the drum frame) similarly to the
photosensitive member coupling member 43 of the Embodiment 9. The
coupling member 143 transmits a driving force to the photosensitive drum 4, by
which the photosensitive drum 4 rotates. Further, the photosensitive drum 4
transmits the driving force to the gear 804, and the gear 804 transmits the driving
force to the gear 803. The gear 803 transmits a driving force to the developing
roller 6, by which the developing roller 6 rotates. That is, the driving force
received from the image forming apparatus main assembly by the coupling
member 143 is branched in the process cartridge to rotate the developing roller 6
and the photosensitive drum 4. Therefore, the coupling member 143 is a
coupling member for receiving a driving force for rotationally driving the
developing roller 6.
[0885] As shown in Figure 151, the spacer 510 and the force receiving portion
51Oe thereof is provided on the same side as the side on which the coupling
member 143 is disposed with respect to the rotation axis direction of the
developing roller 6. In this manner, the spacer 510 and the force receiving
portion 510e of the spacer 510 are arranged. By this, the spacer 510 canbe
switched between the restriction position and the permission position with higher
accuracy relative to the photosensitive drum 4 rotated by the driving force
received from the image forming apparatus main assembly 502. Therefore, the
timing at which the developing roller 6 is brought into contact with the
photosensitive drum 4 and the timing at which it is spaced from the
photosensitive drum 4 can be controlled with high accuracy.
[0886] According to the structure of this embodiment described above, the
same effect as that of the Embodiment 9 can be provided.
<Embodiment 12>
[0887] Referring to Figures 152 and 153, an embodiment of the process
cartridge and the image forming apparatus according to the Embodiment 12 of
the present invention will be described. In this embodiment, structures and
operations different from those of the above-described embodiments will be
mainly described, and description of similar structures and operations will be
omitted. Further, for the structure corresponding to the above-described
embodiment, the same reference numerals and characters are assigned, or the
reference numerals in the first part is changed while the reference numerals and
characters in the second part are the same. This embodiment is the same as
embodiment 9 except for the structure and operation of the spacer.
[0888] Figure 152 is a view of the process cartridge P placed at the second
inner position inside the image forming apparatus main assembly 502 as viewed
from the drive-side. For better illustration, the drive-side cartridge cover
member 820 is shown by omitting portions other than the first contacted surface
820c. Part (a) of Figure 152 shows a state in which the developing unit is
placed at the retracted position. Part (b) of Figure 152 shows a state in which
the developing unit is moving from the retracted position to the developing
position. Part (c) of Figure 152 shows a state in which the developing unit 9 is
placed at the developing position. Figure 153 is a partial cross-sectional view
taken along a plane passing through the line XX shown in Figure (c), and shows
the spacer 810 from below the development cover member 833. Part(a)of
Figure 153 shows a state in which the developing unit 9 is in the retracted
position. Part (b) of Figure 153 shows a state in which the developing unit 9 is
moving from the retracted position to the developing position. Part (c) of Figure
153 shows the state in which the developing unit 9 is in the developing position.
Part (d) of Figure 153 shows a state in which the developing unit 9 is moving
from the developing position to the retracted position.
[0889] The spacer (holding member, spacing member, restricting member)
810 is provided with a supported hole (supported portion) 81Oa which is a second
contact portion, and a projecting portion (supporting portion) 810b projecting
from the supported hole 81Oa in the radial direction of the supported hole 81Oa.
Further, the spacer 810 is provided at the free end of the projecting portion
(holding portion) 81Ob, and has a first contact surface (contact surface) 81Oc as a
first contact portion that contacts the first contacted surface 820c of the drum unit
8. It has a third contact surface 810k adjacent to the contact surface 810c, a
force receiving portion (contact force receiving portion) 81Oe, a spring-hooked
portion 81Og, and a first restricted surface 81Oh.
[0890] Further, the development cover member 833 is provided with a support
portion 833c and a first restriction surface 833h as shown in Figure 153. In the
Embodiment 9, the spacer 510 has been described as being disposed on the side
surface of the development cover member 533, whereas in this embodiment, the
spacer 810 is disposed below the development cover member 833. Theouter
diameter portion of the support portion 833c fits with the inner diameter portion
of the supported hole 810a of the spacer 810, and the support portion 833c
rotatably supports the spacer 810.
[0891] Further, a retracting force receiving portion (separation force receiving
portion) 826a which engages with the first force application surface 540b of the
separation control member 540 is provided on the drive-side bearing 826.
Further, a torsion coil spring 830 as an urging means is provided on the drive-side
bearing 826, and one end of the torsion coil spring 830 is engaged with the
spring-hooked portion 810g. Therefore, the spacer 810 is urged by the torsion
coil spring 830 in the direction of arrow B81 in Figure 153 with the swing axis
8H as the center.
[Separation operation]
[0892] First, referring to Figure 153, the operation of moving the developing
unit 9 from the development position (contact position) to the retracted position
(separation position) will be described.
[0893] As shown in part (c) of Figure 153, when the developing unit 9 is at the
developing position, the torsion coil spring 830 urges the spacer 810 in the
direction of arrow B81 about the supported hole 810a as the center of rotation.
When the developing unit 9 is at the developing position (contact position), the
third contact surface 810k of the spacer engages with the drive-side cartridge
cover 820, so that the spacer 810 is restricted from moving in the direction of the
arrow B81 in part (c) of Figure 153. The position of the spacer 810 shown in
part (c) of Figure 153 is a permission position (second position) of the spacer 810.
[0894] When the separation control member 540 moves in the direction of
W51 in part (d) of Figure 153 from the position shown in part (c) of Figure 153,
the first force application surface 540 b and the retracting force receiving portion
826a of the drive-side bearing 826 come into contact with each other. Further,
when the separation control member 540 moves in the W51 direction and moves
to the second position, the developing unit 9 rotates in the direction of the arrow
VI in part (a) of Figure 152 and moves in the direction from the developing
position to the retracted position.
[0895] Then, when the developing unit 9 rotates in the direction of the arrow
V Iin Figure 152, the spacer 810 mounted to the developing unit 9 also moves in
the direction toward the retracted position, and the third contact surface 810k of
the spacer 810 and the drive-side cartridge cover 820 separate from each other.
[0896] As shown in part (d) of Figure 153, when the first contact surface
(contact portion) 81Oc and the first contacted surface (contacted portion) 820c are separated from each other with the result that a gap T5 is formed, the spacer 810 is rotated in the direction of the arrow B81 in part (d) of Figure 153 by the urging force of the torsion coil spring 830. The spacer 810 rotates until the first restricted surface 81Oh provided on the same surface as the first contact surface
810c comes into contact with the first restriction surface 833h of the development
covermember833. The position of the spacer 810 shown in part (d) of Figure
153 is a restriction position (first position).
[0897] Then, when the separation control member 540 moves from the second
position in the direction of the arrow W52 in part (d) of Figure 153 and returns to
the home position, the developing unit 9 moves in the direction of the arrow V2
in part (b) of Figure 152 and the first contact surface (contact portion) 81Oc of the
spacer 810 placed in in the restriction position and the first contacted surface
(contacted portion) 820c are brought into contact with each other, and the
developing unit 9 is maintained at the retracted position (separated position), as
shown in part (a) of Figure 152 and part (a) of Figure 153. At this time, as in
Embodiment 9, the separation control member 540 is separated from the
retracting force receiving portion 826a, and therefore, the developing unit 9
placed at the retracted position does not impart a load on the separation control
member 540.
[Contact operation]
[0898] Next, the operation of the developing unit 9 moving from the retracted
position to the developing position will be described.
[0899] When the separation control member 540 moves from the home
position in the W52 direction in part (b) of Figure 152, as shown in part (b) of
Figure 153, the second force application surface 540c of the separation control
member 540 and the force receiving portion 810e of the spacer 810 are brought
into contact with each other.
[0900] The force receiving portion 810e has a cam shape in which a plurality
of surfaces are continuously connected. In this embodiment, the force receiving
surface 81Oel and the force receiving surface 810e2 are continuously connected
with each other. When the separation control member 540 moves in the arrow
W52 direction, the separation control member 540 comes into contact with the
force receiving surface 810el to rotate the spacer 810 in the B82 direction against
the urging of the torsion coil spring 830 in the direction of the arrow B81. The
cam shape is profiled such that in the region where the separation control member
540 contacts the force receiving surface 810e1, the spacer 810 rotates in the
direction of the arrow B82 as the separation control member 540 moves in the
arrow W52 direction.
[0901] Further, in the region where the separation control member 540
contacts the force receiving surface 810e2, the amount of rotation of the spacer
810 in the direction of arrow B82 is set to be small with respect to the movement
of the separation control member 540 in the arrow W52 direction. By setting a
region where the rotation amount of the spacer 810 is small, the spacer 810 is
surely moved to an permission position by the movement of the separation
control member 540, and the amount of rotation of the spacer 810 in the direction
of arrow B82 by variation of the movement amount of the separation control
member 540 is suppressed. Part (d) of Figure 153 shows a state in which the
separation control member 540 is in contact with the force receiving surface
810e2.
[0902] By the way, when the spacer 810 rotates in the direction of arrow B82,
the region where the first contact surface 81Oc and the first contacted surface
820c come into contact with each other gradually decreases. Then, when the
spacer 810 rotates in the direction of arrow B82 to an permission position where
the first contact surface 81Oc and the first contacted surface 820c are separated from each other, the developing unit 9 rotates in the V2 direction in part (b) of
Figure 152 to move to the developing position where the developing roller 6 and
the photosensitive drum 4 are in contact with each other as shown in part (c) of
Figure 152.
[0903] At this time, the spacer 810 urged in the direction of arrow B81 by the
torsion coil spring is maintained in the permission position (second position) by
the third contact surface 810k contacting the side surface side of the drive-side
cartridge cover 820 as shown in part (c) of Figure 153.
[0904] As shown in part (c) of Figure 152 and Figure 153 (c), after the
developing unit 9 moves to the contact position, the separation control member
540 returns to the home position and separates from the spacer 810 as in the
Embodiment 9, and therefore, the developing unit 9 placed at the developing
position does not impart a load on the separation control member 540.
[0905] As described above, in this embodiment, the spacer 810 is disposed
below the development cover member 833 and is rotated in the direction of arrow
B82 to move the first contact surface (contact portion) 810c relative to the first
contacted surface 520c in the longitudinal direction of the process cartridge P.
That is, by moving the first contact surface 81Oc relative to the first contacted
surface 520c at least in the longitudinal direction of the process cartridge P (in the
direction of the rotation axis M1 or the rotation axis M2), the spacer 810 is
moved between the permission position (second position) and the restriction
position (first position) in the longitudinal direction of the process cartridge P (the
direction of the rotation axis M1 or the rotation axis M2).
[0906] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
[0907] Further, as has been described referring to Figure 143, the straight line
connecting the rotation axis M1 of the photosensitive drum 4 and the rotation axis
M2 of the developing roller 6 is line N2. Also in this embodiment, when the
region is divided by the line N2, at least a part of the force receiving portion 81Oe
and at least a part of the retracting force receiving portion 826a are disposed in a
region opposite to the region in which the rotation axis K of the development
coupling member 74, with the line N2 as a boundary. Further, when the region
is divided by the line N3 perpendicular to the line N2 and passing through the
contact point between the developing roller 6 and the photosensitive drum 4, at
least a part of the force receiving portion 81Oe and at least a part of the retracting
force receiving portion 826a is disposed in the region opposite to the region in
which the rotation axis M1 of the photosensitive drum 4 exists, with the line N3
as a boundary.
[0908] In this region, the force receiving portion 81Oe receives a force from
the separation control member 540 provided in the main assembly as an external
force. The direction (W52) of the force received by the force receiving portion
81Oe as an external force is the direction in which the developing unit 9 switches
from the spaced state to the contacted state. Therefore, the developing unit 9
can be more reliably switched from the separated state to the contacted state by
the external force received by the force receiving unit 81Oe.
<Embodiment 13>
[0909] Referring to Figure 154, an embodiment of the process cartridge and
the image forming apparatus according to Embodiment 13 of the present
invention will be described. In this embodiment, structures and operations
different from those of the above-described embodiment will be mainly described,
and description of similar structures and operations will be omitted. For the
structure corresponding to that in the above-described embodiment, the same
reference numerals and characters are assigned, or the reference numerals in the first part is changed while the reference numerals and characters in the second part are the same. This embodiment is the same as in embodiment 9 except for the structure and operation of the spacer.
[0910] Figure 154 is a view of the process cartridge P located at the second inner position inside the image forming apparatus main assembly 502 as viewed from the drive-side. For better illustration, the drive-side cartridge cover
member 920 is shown by omitting portions other than the support portion 920a
and the first contacted surface 920c. Part (a) of Figure 154 shows a state in
which the developing unit 9 is moving from the retracted position to the
developing position. Part (b) of Figure 154 shows a state in which the
developing unit 9 is placed at the retracted position. Part (c) of Figure 154
shows a state in which the developing unit 9 is placed at the developing position.
Part (d) of Figure 154 shows a state in which the developing unit 9 is moving
from the developing position to the retracted position.
[0911] In this embodiment as well, as in the Embodiment 9, the spacer (restriction member, holding member) 910 is movable between the permission
position (second position) at which the developing unit 9 can move to the
developing position (contact position) and the restriction position (first position)
in which the developing unit 9 is maintained at the retracted position (separated
position). The spacer 910 is provided with a supported hole (supported portion)
910a and a projecting portion (holding portion) 910b projecting from the
supported hole 910a in the radial direction of the supported hole 910a. Further, the spacer 910 is provided with the first contact surface (contact portion) 91Oc as the first contact portion which contacts the first contacted surface 920c of the
drum unit 8 and which is provided at the free end of the projecting portion
(holding portion) 91Ob, a retraction control surface (at-separation pressed portion)
910d and a contact control surface (at-contact pressed portion) 910e. Thefirst contact surface 910c has an arc shape, and the center of the arc shape is substantially the same as the center of the supported hole 910a. Further,the retraction control surface 910d and the contact control surface 910e are opposed surfaces, and a space 910s exists between the retraction control surface 910d and the contact control surface 910e.
[0912] In this embodiment, the spacer 910 is arranged coaxially with the
developing roller 6. That is, it can rotate about the rotation axis M2 which is the
same as that of the developing roller 6. It is provided with a spacer support
portion 96 formed by extending the core metal of the developing roller 6 in the
longitudinal direction, and by the supported hole 910a of the spacer 910 engaging
with the spacer support portion 96, the spacer 910 is rotatably supported by the
developing roller 6.
[0913] The movable member 950 includes a supported hole 950a, a switching
control portion 950b, a force receiving portion (contact force receiving portion)
950e, and a retracting force receiving portion (separation force receiving portion)
950m.
[0914] The movable member 950 is arranged on the drive-side cartridge cover
920, and by the supported hole 950a engaging with the support portion 920a
provided on the drive-side cartridge cover 920, the movable member 950 is
rotatably supported by the drive-side cartridge cover 920.
[0915] The movable member 950 is adjacent to the spacer 910, and the
switching control portion 950b is disposed in the space 910s between the
retraction control surface 910d and the contact control surface 910e. Further, a
space 950s is provided between the force receiving portion 950e of the movable
member 950 and the retracting force receiving portion 950m.
[Separation operation]
[0916] Hereinafter, referring to Figure 154, the operation in this embodiment will be described.
[0917] First, the operation of the developing unit 9 moving from the developing position to the retracted position will be described. As shown in part
(c) of Figure 154, when the developing unit 9 is placed at the developing position
(contact position), the spacer 910 is in the permission position (second position) in which the first contact surface (contact portion) 910c and thefirst contacted
surface (contacted surface) 920c are separated from each other.
[0918] When the separation control member 540 moves in the W51 direction as shown in part (d) of Figure 154 from the position shown in part (c) of Figure
154, the first force application surface 540b and the retracting force receiving
portion 950m of the movable member 950 come into contact with each other.
Further, when the separation control member 540 moves in the W51 direction,
the movable member 950 rotatably supported by the drive-side cartridge cover
920 receives a force from the first force application surface 540b and is rotated in
the direction indicated by the arrow B Iin part (d) of Figure 154.
[0919] When the movable member 950 rotates in the direction of arrow B1, the at-separation contact portion of the switching control portion 950b contacts
the retraction control surface (at-separation contacted portion) 910d, and the
spacer 910 is rotated in the arrow B3 in part (d) of Figure 154. By this, the
spacer 910 rotates and moves to the restriction position (first position) where the
first contact surface (contact portion) 910c contacts the first contacted surface
(contacted portion) 920c, and the developing unit 9 moves to the retracted
position (separated position) shown in part (a) of Figure 154.
[0920] At this time, since the first contact surface 910c has an arc shape, the direction of the reaction force from the first contacted surface 920c is toward the
center of the arc shape. The arcuate center of the first contact surface 910c is
substantially the same as the center of the supported hole 91Oa and the center of the developing roller 6. The first contact surface 910c directs the reaction force direction from the first contacted surface 920c toward the rotation center of the spacer 910, so that the rotation moment of the spacer generated from the reaction force from the first contacted surface 920c is suppressed. As a result, the spacer
910 can stably maintain the restriction position (first position) at the retracted
position, and the developing unit 9 can stably maintain the retracted position.
The shapes of the contact surface 910c and the first contacted surface 920c are
selected such that the developing roller 6 and the photosensitive drum 4 are
spaced by the gap T2 in part (a) of Figure 154, at the retracted position where the
first contact surface 910c contacts the first contacted surface 920c.
[0921] When the separation control member 540 moves from the second
position in the W52 direction in part (b) of Figure 154 and moves to the home
position, the portion having the first force application surface 540b and the
second force application surface 540c of the separation control member 540
moves in the space 950s of the movable member 950 are applied. That is, the
first force application surface 540b and the second force application surface 540c
located at the home position are in a state of being separated from the movable
member 950, and therefore, the developing unit 9 placed at the retracted position
does not impart a load on the separation control member 540.
[Contact operation]
[0922] Next, the operation of the developing unit 9 moving from the retracted
position to the developing position will be described. When the separation
control member 540 moves from the home position in the arrow W52 direction in
part (a) of Figure 154, as shown in part (b) of Figure 154, the second force
application surface 540c of the separation control member 540 and the force
receiving portion 950e of the movable member 950 come into contact with each
other, and the movable member 950 rotates in the arrow B2 direction in part (b) of Figure 154. When the separation control member 540 moves to the first position and the movable member 950 rotates, the at-contact pressing portion of the switching control portion 950b contacts the contact control surface (contact pressed portion) 910e provided on the spacer 910, and the spacer 910 is rotationally moved in the B4 direction in part (b) of Figure 154. As a result, the first contact surface 910c and the first contacted surface 920c are separated from each other, and the spacer 910 moves to the permission position.
[0923] When the spacer 910 moves to the permission position, the developing
unit 9 rotates in the V2 direction in part (b) of Figure 154, and moves to the
developing position where the developing roller 6 and the photosensitive drum 4
contact each other (state in part (c) of Figure 154). Then, when the separation
control member 540 moves from the first position to the home position, the
portion of the separation control member 540 having the first force application
surface 540b and the second force application surface 540c moves in the space
950s of the movable member 950 and develops to maintain the state away from
the developing unit 9.
[0924] In this embodiment, the separation control member 540 moves in the
space 950s of the movable member 950 when moving from the first position to
the home position and when moving from the second position to the home
position, and the state in which the separation control member 540 and the
movable member 950 are separated from each other is maintained. The
structure for preventing the separation control member 540 from receiving a load
from the developing unit 9 at the home position is not limited to described
examples, and the structure as shown in Figure 155 may be employed.
[0925] That is, the structure may be such that the space 950s of the movable
member 950 is reduced, and the force receiving portion (contact force receiving
portion) 950e and the retracting force receiving portion (separation force receiving portion) 950m of the movable member 950 are brought into contact with the first force application surface 540b and the second force application surface 540c of the separation control member 540, at the same time. Further, the structure may be such that when the process cartridge P is mounted to the image forming apparatus main assembly 502, the receiving portion 950e and the retracting force receiving portion 950m sandwich the first force application surface 540b and the second force application surface 540c of the separation control member 540 and are made integral, or they may be integrated by bonding using double-sided tape or the like. However, when the movable member 950 and the separation control member 540 are structured in this manner, the space
910s between the switching control portion 950b and the retraction control
surface 910d and the contact control surface 910e is structured as follows. As
shown in Figure 155, the space 910s in which the switching control portion 950b
is provided is expanded, and when the separation control member 540 is placed at
the home position, the switching control portion 950b is in a state of being
separated from the retraction control surface 910d and the contact control surface
910e. That is, when the developing unit 9 is placed at the retracted position, the
switching control portion 950b and the retraction control surface 910d are
separated from each other, and therefore, the developing unit 9 can suppress the
load applied to the separation control member 540.
[0926] Further, also when the developing unit 9 is placed at the developing
position, the switching control portion 950b and the contact control surface 910e
are separated from each other, and therefore, the developing unit 9 suppresses the
load applied to the separation control member 540.
[0927] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
[0928] In the structure shown in Figure 155, the force receiving portion 950e of the movable member 950 of the developing unit 9 receives the force from the separation control member 540 mounted in the main assembly as an external force, as in the embodiments described in the foregoing. The direction (W52) of the force received by the force receiving portion 950e as an external force is the direction in which the developing unit 9 switches from the separation state to the contacted state. Therefore, the developing unit 9 can be more reliably switched from the separated state to the contacted state by the external force received by the force receiving unit 950e.
<Embodiment 14>
[0929] Referring to Figures 156 and 157, an embodiment of the process cartridge and the image forming apparatus according to the 14th embodiment of the present invention will be described. In this embodiment, structures and
operations different from those of the above-described embodiment will be
mainly described, and description of similar structures and operations will be omitted. Further, for the structure corresponding to the above-described
embodiment, the same reference numerals and characters are assigned, or the
reference numerals in the first part is changed while the reference numerals and
characters in the second part are the same. This embodiment is the same as
embodiment 9 except for the structure and operation of the spacer.
[0930] Figures 156 and 157 are illustrations of the process cartridge P placed at the second inner position inside the image forming apparatus main assembly
502 as viewed from the drive-side. For better illustration, the drive-side
cartridge cover 1120 is shown with the omission of the portions other than the
first contacted surface 1120c and the spring-hooked portion 1120e.
[0931] First, referring to Figure 156, the operation of the developing unit 9 moving from the developing position (contact position) to the retracting position
(separated position) will be described.
[0932] Also, in this embodiment, similarly to the Embodiment 9, the spacer 1110 can move the permission position where the developing unit 9 can move to
the developing position and the restriction position where the developing unit 9 is
maintained in the retracted position.
[0933] Further, the separation control member 540 mounted in the image forming apparatus main assembly 502 is capable of moving the first position for
moving the spacer (restriction member holding member) to a permission position
(second position) and the second position for moving the spacer 1110 to the
restriction position (first position). Further, the separation control member 540
is structured to be movable between the first position and the second position to
the home position where the separation control member 540 does not contact the
force receiving portion 1110e or the retracting force receiving portion 1133a.
[0934] Part (a) of Figure 156 shows a state in which the developing unit 9 is in the developing position and the separation control member 540 is in the first position. Part (b) of Figure 156 and Figure 156 (c) show a state in which the
separation control member 540 is moving from the first position to the second
position and the developing unit 9 is moving from the developing position to the
retracted position. Part (d) of Figure 156 shows a state in which the developing
unit 9 is in the retracted position and the separation control member 540 is in the
home position.
[0935] As shown in part (a) of Figure 156, the spacer 1110 provided with a retracting force receiving portion 111m is arranged on the development cover
member 1133 as in the Embodiment 9. That is, the spacer 1110 is rotatably
supported by the development cover member 1133 by engaging the supported
hole (supported portion) 111Oa, which is the second contact portion, with the
supporting portion 1133c.
[0936] Further, the spacer 1110 is provided with a spring-hooked portion
11lOg projecting in the axial direction of a supported hole 1110a. Thedrive
side cartridge cover 1120 also has a spring-hooked portion 1120e projecting from
the first contacted surface 1120c in the axial direction of the supported hole
1110a, and the tension spring 1130 as a holding portion urging member is
assembled to a spring-hooked portion 11Og and the spring-hooked portion 1120e.
[0937] The spring-hooked portion 111Og corresponds to the point of action of
the tension spring 1130, and the tension spring 1130 applies a force to the spring
hooked portion 11Og in the direction of the arrow F5 in part (a) of Figure 156.
Here, the direction of the arrow F5 in part (a) of Figure 156 is substantially
parallel to the line connecting the spring-hooked portion 111Og and the spring
hooked portion 1120e. That is, as shown in part (a) of Figure 156, when the
developing unit 9 is placed at the developing position, the tension spring 1130
applies the force to the spacer 1110 in the direction of the arrow F5 in part (a) of
Figure 156 to urge the spacer 1110 about the supported hole 11Oa in the
direction of the arrow B2 in part (a) of Figure 156.
[Separation operation]
[0938] The separation control member 540 is structured to be movable from
the first position shown in part (a) of Figure 156 in the arrow W51 direction in
part (a) of Figure 156. When the separation control member 540 moves in the
W51 direction, the first force application surface 540b and the retracting force
receiving portion 111m of the spacer 1110 come into contact with each other,
and the third contact surface 1110k of the spacer 1110 rotates in the direction of
the arrow B1 until it comes in contact with the spring-hooked portion 1120e
(State shown in part (b) of Figure 156). Further, when the separation control
member 540 moves in the direction of W51 to the second position shown in part
(c) of Figure 156, the developing unit 9 rotates in the direction of the arrow VI in part (b) of Figure 156 and moves from the developed position to the retracted position. Further, the third contact surface 1110k of the spacer is separated from the spring-hooked portion 1120e and rotates in the direction of the arrow B1 in part (b) of Figure 156 until the first restricted surface 11Oh comes into contact with the first restriction surface 1133h, and to the restriction position (1st position). (State shown in part (c) of Figure 156) At this time, the spring hooked portion 111g moves in the direction of the arrow B1 in part (b) of Figure
156 with the rotation of the spacer 1110, and therefore, the action direction of the
tension spring 1130 switches from the direction of the arrow F5 in part (a) of
Figure 156 to the direction of the arrow F6 in part (c) of Figure 156. That is, as
shown in part (c) of Figure 156, the tension spring 1130 applies a force to the
spacer 1110 in the direction of the arrow F6 in part (c) of Figure 156, and the
spacer 1110 is urged in the direction of the arrow B Iin part (c) of Figure 156
about the supported hole 1110a.
[0939] By switching the direction in which the tension spring 1130 acts on the
spacer in this manner, the direction in which the tension spring 1130 urges the
spacer 1110 is the same as the direction in which the spacer 1110 moves by the
movement of the separation control member 540 in the W51 direction, and
therefore, the spacer 1110 can be stably moved from the permission position
(second position) to the restriction position (first position).
[0940] Then, when the separation control member 540 moves from the second
position in the W52 direction in part (c) of Figure 156 to the home position, the
developing unit 9 moves in the direction of the arrow V2 in Figure 156 (c), by
which the first contact surface (contact portion) 111Oc of the spacer 1110 placed
at the restriction position (first position) and the first contacted surface (contacted
portion) 1120c of the drive-side cartridge cover 1120 are brought into contact
with each other. At this time, in the spacer 1110, the supported hole (supported portion) 11Oa is in contact with the supporting portion 1133c of the development cover member 1133. Therefore, the portion connecting the supported hole
1110a of the spacer 1110 and the first contact surface 110c functions as a
holding portion for holding the development cover member 1133, similarly to the
projecting portion (holding portion) 510b of the Embodiment 9. Function. As
a result, the developing unit 9 is maintained in the retracted position (separated
position) (the state shown in part (d) of Figure 156). At this time, as in the
Embodiment 9, the separation control member 540 placed at the home position is
separated from the spacer 1110, so that the developing unit 9 placed at the
retracted position does not impart a load on the separation control member 540.
[0941] Further, in the state where the developing unit 9 shown in part (d) of
Figure 156 is placed at the retracted position, the tension spring 1130 applies a
force in the direction of the arrow F6 in part (d) of Figure 156 to the spacer 1110
to urge the spacer 1110 in the direction of the arrow B1, and therefore, the spacer
1110 can stably maintain the restriction position (first position), and the
developing unit 9 can stably maintain the retracted position (separated position).
[Contact operation]
[0942] Next, referring to Figure 157, the operation of moving the developing
unit 9 from the retracted position (separated position) to the developing position
(contact position) will be described. Part (a) of Figure 157 shows a state in
which the developing unit 9 is in the retracted position and the separation control
member 540 is in the home position. Part (b) of Figure 157 shows a state in
which the separation control member 540 is moving from the home position
toward the first position and the developing unit 9 is moving from the retracted
position to the developing position. Part (c) of Figure 157 shows a state in
which the developing unit is in the developing position and the separation control
member 540 is in the first position.
[0943] When the separation control member 540 moves from the home
position in the arrow W52 direction in part (a) of Figure 157, the second force
application surface 540c of the separation control member 540 and the force
receiving portion 1110e of the spacer 1110 are brought into contact with each
other to rotate the spacer 1110 in the direction of the arrow B2 in part (b) of
Figure 157. When the separation control member 540 moves to the first
position and the spacer 1110 rotates, the first contact surface 11Oc and the first
contacted surface 1120c of the drive-side cartridge cover 1120 are separated from
each other, and the spacer 1110 is moved to the permission position (second
position). When the spacer 1110 moves to the permission position, the
developing unit 9 rotates in the V2 direction in part (b) of Figure 157 and moves
to the developing position (contact position) in which the developing roller 6 and
the photosensitive drum 4 contact with each other (contact position) (state shown
part (c) of Figure 157). Since the separation control member 540 moved to the
first position is separated from the spacer 1110 of the developing unit 9 moved to
the developing position, the separation control member 540 is not subjected to a
loaded from the developing unit 9.
[0944] Further, when the developing unit 9 moves from the retracted position
to the developing position in this manner, the spring-hooked portion 111Og of the
spacer 1110 moves in the direction of the arrow B2 in part (b) of Figure 156 with
the rotation of the spacer 1110. The direction of action of the tension spring
1130 is switched from the direction of the arrow F6 in part (a) of Figure 157 to
the direction of the arrow F5 in part (c) of Figure 157, and the direction in which
the tension spring 1130 urges the spacer 1110 is switched from the direction of
the arrow B Iin part (a) of Figure 157 to the direction of the arrow B2. That is,
the urging direction of the spacer 1110 by the tension spring 1130 becomes the
same as the rotational direction of the spacer 1110 by the movement of the separation control member 540 in the W52 direction, and therefore, the spacer
1110 can be stably moved from the restriction position (first position) to the
permission position (second position).
[0945] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
[0946] Further, in this embodiment, the urging direction of the spacer 1110 by
the tension spring can be made to be the same as the rotational direction of the
spacer by the separation control member 540, so that the movement of the spacer
1110 between the permission position and the restriction position can be
stabilized. That is, the control of the attitude of the developing unit 9 can be
stabilized.
[0947] Further, in this embodiment, when the developing unit 9 is in the
developing position, the separation control member 540 is stopped at the first
position, but the present invention is not limited to this Example. As in the
Embodiment 9, the structure may be such that the separation control member 540
moved from the second position to the first position may be returned from the
first position to the home position and then it is stopped.
<Embodiment 15>
[0948] Referring to Figures 158, 159 and 160, the process cartridge and the
image forming apparatus according to the Embodiment 15 of the present
invention will be described. In this embodiment, structures and operations
different from those of the above-described embodiment will be mainly described,
and description of similar structures and operations will be omitted. Further, for
the structure corresponding to the above-described embodiment, the same
reference numerals and characters are assigned, or the reference numerals in the
first part is changed while the reference numerals and characters in the second part are the same. This embodiment is the same as in Embodiment 9 except for the structure and operation of the spacer. In the Embodiment 9, the spacer 510 is structured to move between the restriction position and the permission position by rotating relative to the developing unit (or developing frame) or the drum unit
(or drum frame), but the movement of the spacer 510 relative to the developing
frame is not limited to rotation. That is, referring to the Embodiment 9, the
spacer 510 is modified to have a structure in which the spacer 510 moves in a
predetermined direction relative to the developing frame (linear movement, for
example) between the restriction position and the permission position. Further,
in this embodiment, the spacer 1210 is supported by the drum unit (or the drum
frame) as in the other Example 1 of Embodiment 9.
[0949] In this embodiment as well as in the Embodiment 9, the spacer 1210 is
movable between the permission position (second position) in which the
developing unit 9 can move to the developing position and the restriction position
(first position) in which the developing unit 9 is maintained in the retracted
position.
[0950] Further, the separation control member 540 mounted in the image
forming apparatus main assembly 502 can move between the first position for
moving the spacer 1210 to the permission position and the second position for
moving the spacer 1210 to the restriction position. Further, the separation
control member 540 is structured to be movable to a home in which the
separation control member 540 does not contact the force receiving portion
(contact force receiving portion) 1210e and the retracting force receiving portion
(separation force receiving portion) 1233a between the first position and the
second position.
[0951] In Embodiment 9, the spacer 510 is mounted on the developing unit 9,
but in this embodiment, the spacer 1210 is mounted on the drive-side cartridge cover member 1220. Figure 158 is a perspective view illustrating the spacer
1210 mounted on the drive-side cartridge cover member 1220. Asshownin
Figure 158, a support portion 1220f is provided on the drive-side cartridge cover
member 1220, and the supported hole (supported portion) 1210a of the spacer
1210 engages with the support portion 1220f, by which the spacer 1210 is
supported by the drive-side cartridge cover member 1220. The supported hole
1210a has an oblong round hole shape, and the spacer 1210 is supported movably
in the directions of arrows B3 and B4 in Figure 158. The directions of arrows
B3 and B4 in Figure 158 are substantially parallel to the directions of arrows ZI
and Z2 in Figure 5.
[0952] The spacer 1210 is provided with a projecting portion 121Ob projecting
from the supported hole 1210a. Further, the spacer 1210 is provided with a first
contact surface (contact portion) 1210c corresponding to the first contact portion,
at the free end of the projection 1210b, and is provided with a first restricted
surface 1210h connecting with a first contact surface 1210c on the side surface of
the projection 121Ob. Further, the spacer 1210 is provided with a force
receiving portion (contact force receiving portion) 1210e in the direction of arrow
B4 of the supported hole 1210a in Figure 158.
[Separation operation]
[0953] Referring first to Figure 159, the operation of the developing unit 9
moving from the developing position (contact position) to the retracting position
(separated position) will be described. Figure 159 is a view of the process
cartridge P int the second inner position inside the image forming apparatus main
assembly 502 as viewed from the drive-side. For better illustration, the drive
side cartridge cover 1220 is shown by omitting portions other than the support
portion 1220f. Part (a) of Figure 159 shows a state of the developing position of
the developing unit 9. Part (b) of Figure 159 shows a state in which the developing unit is moving from the developing position to the retracted position.
Part (c) of Figure 159 shows a state in which the developing unit 9 is in the
retracted position.
[0954] As shown in part (a) of Figure 159, the development cover member
1233 is provided with a restriction portion 1233e projecting in the swing axis K
direction (outside in the longitudinal direction) of the developing unit 9. When
the developing unit 9 is located at the developing position, the first restricted
surface 1210h of the spacer 1210 engages with the restriction portion 1233e, so
that the movement of the spacer 1210 in the direction of the arrow B4 in part (a)
of Figure 159 is restricted. The position of the spacer 1210 shown in part (a) of
Figure 159 is a permission position (second position) of the spacer 1210.
[0955] The separation control member 540 moves in the arrow W51 direction
in Figure (a), and the first force application surface 540b comes into contact with
the retracting force receiving portion (separation force receiving portion) 1233a
of the development cover member 1233. Further, when the separation control
member 540 moves in the W51 direction and moves to the second position, the
developing unit 9 rotates in the direction of the arrow VI in part (b) of Figure 159
and moves from the developing position to the retracted position. At this time,
the restriction portion 1233e of the development cover member 1233 moves with
the rotation of the developing unit 9, and therefore, the first restricted surface
1210h is separated from the restriction portion 1233e, and the spacer 1210 is
moved in the direction of the arrow B4 in part (b) of Figure 159 by its own
weight. The position of the spacer 1210 shown in part (b) of Figure 159 is the
restriction position (first position).
[0956] Then, when the separation control member 540 moves from the second
position in the arrow W52 direction in part (b) of Figure 159 to returns to the
home position, the developing unit 9 moves in the direction of the arrow V2 in part (b) of Figure 159, and the first contact surface 1210c of the positioned spacer placed in the restriction position and the restriction portion 1233e are brought into contact with each other, and the developing unit 9 is maintained in the retracted position (state shown in part (c) of Figure 159). At this time, as in the
Embodiment 9, the separation control member 540 is separated from the spacer
1210, so that the developing unit 9 located at the retracted position does not apply
a load on the separation control member 540.
[Contact operation]
[0957] Next, referring to Figure 160, the operation of moving the developing
unit 9 from the retracted position (separation position) to the developing position
(contact position) will be described. Figure 160 is a view of the process
cartridge P placed at the second inner position inside the image forming apparatus
main assembly 502 as viewed from the drive-side. For better illustration, the
drive-side cartridge cover 1220 is shown by omitting portions other than the
support portion 1220f.
[0958] Part (a) of Figure 160 shows a state in which the developing unit 9 is
placed at the retracted position. Part (b) of Figures 160 and part (c) of Figure
160 show a state in which the developing unit 9 is moving from the retracted
position to the developing position. Part (c) of Figure 160 shows a state in
which the developing unit 9 is placed at the developing position.
[0959] When the separation control member 540 moves from the home
position in the arrow W52 direction in part (a) of Figure 160, the second force
application surface 540c of the separation control member 540 and the force
receiving portion (contact force receiving portion) 1210e of the spacer 1210 come
into contact with each other (part (b) of Figure 160). Further, when the
separation control member 540 moves in the arrow W52 direction in part (b) of
Figure 160, the spacer 1210 urged by the separation control member moves in the direction of B3 in part (b) of Figure 160, and the spacer 1210 moves to the permission position (second position) where the first contact surface 1210c and the restriction portion 1233e are separated from each other (part (c) of Figure
160). When the spacer moves to the permission position, the developing unit 9
rotates in the V2 direction in part (c) of Figure 160 and moves to the developing
position where the developing roller 6 and the photosensitive drum 4 are in
contact with each other (part (d) of Figure 160). After the developing unit 9
moves to the developing position, the separation control member 540 returns to
the home position and separates from the spacer 1210, as in the Embodiment 9,
and therefore, the developing unit 9 placed at the developing position does not
impart a load on the separation control member 540.
[0960] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
[0961] As described above, in this embodiment, the spacer 1210 supported by
the drive-side cartridge cover member 1220 (drum unit 8) is linearly moved
between the permission position (second position) and the restriction position
(first position), by which the position of the developing unit 9 relative to the drum
unit 8 can be changed.
<Embodiment 16>
[0962] Next, referring to Figures 161 to 164, Embodiment 16 will be
described. In this embodiment, structures and operations different from those of
the above-described embodiment will be mainly described, and description of
similar structures and operations will be omitted. Further, for the structure
corresponding to the above-described embodiment, the same reference numerals
and characters are assigned, or the reference numerals in the first part is changed
while the reference numerals and characters in the second part are the same. In this embodiment, a case where the process cartridge separation/contact mechanism is arranged only on the drive-side will be described.
[Upper placement of spacer]
[0963] In Embodiments 1 to 15, the spacers are disposed in the neighborhood of the photosensitive drum and the developing roller, but the present invention is not limited to such examples, and the spacers are placed at arbitrary positions on
the drive-side cartridge cover member according to the applied condition of
structure. Here, referring to Figures 161 and 162, as an example thereof, a case
where the spacer is provided above the swing axis K of the developing unit will
be described.
[0964] Figure 161 is an exploded perspective view of the drive-side cartridge cover member 1716, the tension spring 1753, the spacer 1751A, the movable
member 1752A, and the development cover member (a part of the developing
frame) 1728, and part (b) of Figure 161 shows a view as seen from the non-drive
side direction. Figure 162 is a cross-sectional view of the process cartridge 1700A, and is a view illustrating the operation relating to the separation/contact
mechanism. Part (a) of Figure 162 shows a state of separation of the developing
unit 1709A, and part (b) of Figure 162 shows a state of contact of the developing
unit 1709A.
[0965] First, referring to Figure 162, the spacer (holding member, restricting
member) 1751A will be described. The supported hole 1751Aa is rotatably
supported by the first supporting portion (support portion) 1728Ac of the
development cover member 1728A provided on the side opposite to the
developing roller 1706 with respect to the swing axis K of the developing unit
1709A. The separation holding portion (holding portion) 1751Ab projects from
the supported hole 175lAa in the downstream direction of V2, which is the
rotational direction when the developing unit is in the contact position, and is provided with a contact surface (contact portion) 175lAc at its free end. Further, it is provided with a second restricted surface 1751Ak adjacent to the contact surface 1751Ac. The second pressed portion 1751Ad projects from the supported hole 175lAa in the direction opposite to the swing axis K. Further, the free end of the second pressed portion 175lAd has a second pressed surface
1751Ae on the surface on the counterclockwise B1 direction side about the
supported hole 1751Aa. A spring-hooked portion 1751Ag is provided on a
downstream side of the second pressed surface 1751Ae with respect to the
counterclockwise B Idirection about the supported hole 1751Aa. Further, the
spring-hooked portion 175lAg is disposed on a downstream side of the straight
line connecting the supported hole 175lAa and the spring-hooked portion
1752As of the movable member 1752A which will be described hereinafter in the
counterclockwise direction about the spring-hooked portion 1752As.
[0966] Next, the movable member 1752A will be described. The oblong
supported hole 1752Aa is rotatably supported by the second supporting portion
1728Ak of the development cover member 1728A provided at substantially the
center of the movable member 1752A. The second pressing surface (at-contact
pressing portion) 1752Ar is opposed to the second pressed portion (at-contact
pressed portion) 1751Ae of the spacer 1751A in the counterclockwise direction
B1 about the first supporting portion 1728Ac of the development cover member
1728A. The spring-hooked portion 1752As is provided between the oblong
supported hole 1752Aa and the second pressing surface 1752Ar. The other
structures of the movable member 1752A are the same as those in the
Embodiment 1, and therefore, the description thereof will be omitted. Next, the
drive-side cartridge cover member 1716A will be described. The drive-side
cartridge cover member 1716A is provided with a contact surface (contacted
portion) 1716Ac which contacts the contact surface 175lAc of the spacer 1751A in a state in which the developing unit 1709A is separated (part (a) of Figure 162).
Further, it is provided with a second restriction surface 1716Ac adjacent to the
contact surface 1716Ac on the swing axis K side.
[0967] Next, the tension spring 1753 is mounted to the spring-hooked portion
175lAg of the spacer 1751A and to the spring-hooked portion 1752As of the
movable member 1752A. Then, the tension spring 1753 applies an urging force
in the counterclockwise direction B1 about the supported hole 1751Aa of the
spacer 1751A.
[Contact and separation operations]
[0968] Next, the operation of the contact separation mechanism will be
described. First, as shown in part (a) of Figure 162, when the developing unit
1709A is in the development spaced state in the retracted position (spaced
position), the contact surface 175lAc of the spacer 1751A is in contact with the
contact surface 1751Ac of the drive-side cartridge cover member 1716A. By
this, the spacing amount P1 between the photosensitive drum 1704 and the
developing roller 1706 is maintained. At this time, the spacer 1751A is in the
restriction position (first position).
[0969] Next, the operation of changing from the state of development
separation to the state of development contact shown in part (b) of Figure 162
will be described. By the separation control member 196R (not shown) of the
main assembly 170 moving in the W42 direction and contacting and pressing
against the second force receiving portion (contact force receiving portion)
1752An, the movable member 1752A is rotated about the second supporting
portion 1728Ak in the BB direction (clockwise direction). Then, by the second
pressing surface 1752Ar coming into contact with the second pressed surface
175lAe, the spacer 1751A is rotated clockwise around the first supporting
portion 1728Ac in the B2 direction to move from the restriction position (first position) to the permission position (second position). By this, the developing unit 1709A rotates around the swing axis K and moves to the developing position
(contact position), so that the developing roller 1706 and the photosensitive drum
1704 come into contact with each other (development contact state).
[0970] Next, the operation of changing from the development contact state
shown in part (b) of Figure 162 to the development separation state shown in part
(a) of Figure 162 will be described. From the state shown in part (b) of Figure
162, the separation control member 196R (shown) of the apparatus main
assembly 170 moves in the direction of W41 to contact to the first force receiving
portion (retracting force receiving portion, separating force receiving portion)
1752Ak. By this, the movable member 1752A is rotated about 1728 Ak in the
opposite direction (counterclockwise direction), that is, in the BB direction.
Then, the developing frame pressing surface (at-separation pressing portion)
1752Aq presses the pressed surface (at-separation pressed portion) 1728Ah of the
development cover member 1728, by which the developing unit 1709A is rotated
about the swing axis K. At this time, the spacer 1751A rotates in the
counterclockwise direction B1 about the first supporting portion 1728Ac by the
action of the tension spring 1753. By this, the contact surface 175lAc of the
spacer 1751A comes into contact with the contact surface 175lAc of the drive
side cartridge cover member 1716A, so that the separated state of the developing
unit 1709A is maintained.
[0971] As described above, according to this embodiment, the arrangement
can be such that the spacer 1751A is disposed on the side opposite to the side in
which the second force receiving portion (contact force receiving portion)
1752An and the first force receiving portion (retracting force receiving portion,
separating force receiving portion) are disposed, with respect to the swing axis
1752 Ak (or above the swing axis K).
[0972] Further, the spacer 1751A of this embodiment has a structure in which
it can move between the first position and the second position by receiving a
force from the separation control member 196R of the apparatus main assembly
170 byway of the movable member 1752A. However, the spacer 1751A of this
embodiment may receive the force directly from the separation control member
196R of the apparatus main assembly 170 without using the movable member as
shown in the Embodiment 9, and may move between the first position and the
second position.
<Another Example of Embodiment 16>
[0973] In this alternative embodiment, referring to Figures 163 and 164, a
structure in which the developing unit is held in a spaced state by hooking the
spacer on the drum unit will be described. Figure 163 is an exploded
perspective view of the tension spring 1753, the spacer 1751A, the movable
member 1752A, and the development cover member 1728, wherein part (a) of
Figure 163 is a view as seen from the drive-side and part (b) of Figure 163 is a
view as seen from the non-drive-side. Figure 164 is a sectional view of the
process cartridge 1700B, and illustrates the operation relating to the
separation/contact mechanism, in which (a) shows the state of separation of the
developing unit 1709A, and (b) shows the state of contact of the developing unit
1709A.
[0974] First, referring to Figures 163 and 164, the drum frame 1715B will be
described. The drum frame 1715B has an engaging portion (drum unit (drum
frame) side engaging portion) 1715Bb on the side opposite to the side in which
the developing roller 1706 with respect to a line connecting the swing axis K of
the developing unit 1709B and the photosensitive drum 1704 axis. The
engaging portion 1715Bb extends toward the developing unit 1709B, and a
contacted surface 1715Bc facing the drum unit 1708B direction is provided at the free end thereof. Then, the engaging portion 1715Bb is provided with a second restriction surface 1715Bd, adjacent to the contacted surface 1715Bc, which faces in the direction away from the photosensitive drum 1704.
[0975] Next, the spacer 1751B will be described. The supported hole
(supported portion) 1751Ba is rotatably supported by the first supporting portion
1728Bc of the development cover member (part of the developing frame) 1728B.
That is, the supported hole (supported portion) 1751Ba is in contact with the first
supporting portion 1728Bc. Further, the first supporting portion 1728Bc is
disposed on the side opposite, with respect to the swing axis K of the developing
unit 1709B, to the side having the developing roller 1706, the second force
receiving portion (contact force receiving portion) 1752Bn, and the first force
receiving portion (retracting force receiving portion, separation) 1752Bk. The
separation holding portion (holding portion, spacer side engaging portion)
1751Bb is provided so as to project (extend) from the supported hole 1751Ba
toward the engaging portion 1715Bb of the drum frame 1715B. In other words,
the separation holding portion 1751Bb is provided so as to project from the
supported hole 1751Ba in the direction from the downstream to the upstream in
the V2 direction in which the developing unit 1709 rotates from the separated
state to the contact state. At the free end of the separation holding portion
1751Bb, a contact surface (contact portion) 1751Bc facing the direction of the
developing unit 1709B is provided. The contact surface 1751Bc is disposed so
as to abut to the contacted surface 1715Bc of the drum frame 1715 in the state
that the developing unit 1709A is separated. Further, the separation holding
portion 1751Bb is provided with a second restricted surface 1751Bk which is
adjacent to the contact surface 1751Bc and which faces toward the photosensitive
drum 1704 (the direction opposite to the direction toward the second restriction
surface 1715Bd). The second pressed portion 1751Bd projects from the supported hole 1751Ba in the direction opposite to the swing axis K. Further, the free end of the second pressed portion 1751Bd has a second pressed surface
(at-contact force receiving portion) 1751Be on the surface on the downstream
side in the counterclockwise B Iabout the supported hole 1751Ba. The spring
hooked portion 1751Bg is provided on the separation holding portion 1751Bb at a
position between the supported hole 1751Aa and the contact surface 1751Bc.
Further, the spring-hooked portion 1751Bg is disposed on the downstream side in
the counterclockwise direction about the spring-hooked portion 1752Bs with
respect to the straight line connecting the supported hole 1751Ba and the spring
hooked portion 1752Bs of the movable member 1752B which will be described
hereinafter.
[0976] Next, the movable member 1752B will be described. The oblong
supported hole 1752Ba is rotatably supported by the second supporting portion
1728Bk of the development cover member 1728B provided at substantially the
center of the movable member 1752B. The second pressing surface (at-contact
pressing portion) 175Br is provided so as to oppose the second pressed portion
1751Be of the spacer 1751B in the counterclockwise BI direction about the first
supporting portion 1728Bc of the development cover member 1728B. The
spring-hooked portion 1752Bs is provided between the oblong supported hole
1752Ba and the second pressing surface 1752Br. Further, the movable member
1752B is provided with the second force receiving portion (contact force
receiving portion) 1752Bn and the first force receiving portion (retracting force
receiving portion, separating force receiving portion) 1752Bk which receive a
force from the separation control member 196R (not shown) of the apparatus
main assembly 170. The other structures of the movable member 1752B are the
same as those in the Embodiment 1, and therefore, the description thereof will be
omitted.
[0977] The tension spring 1753 is mounted to the spring-hooked portion
1751Bg of the spacer 1751B and the spring-hooked portion 1752Bs of the
movable member 1752B. Then, the tension spring 1753 urges the spacer 1751A
in a direction of rotating in the B1 direction (counterclockwise in the drawing)
about the supported hole 1751Aa of the spacer 1751A.
[Contact and separation operations]
[0978] Next, the contact operation and the separation operation will be
described. First, when the developing unit 1709B is in the separated state as
shown in part (a) of Figure 164, the contact surface 1751Bc of the spacer 1751B
is in contact (engagement) with the contacted surface 1715Bc of the drum frame
1715B, and the supported hole (supported portion) 1751Ba is in contact with the
first supporting portion 1728Bc. Therefore, the movement (rotation) in the V2
direction from the retracted position (separation position) of the developing unit
1709B to the developing position (contact position) is restricted so that the
developing roller 1706 maintains the spacing amount P1 from the photosensitive
drum1704. The position of the spacer 1751B at this time is the restriction
position (first position).
[0979] Next, the operation of shifting the developing unit 1709B from the
separated state to the contacted state as shown in part (b) of Figure 164 will be
described. The separation control member 196R (not shown) moves in the W42
direction and presses the second force receiving portion (contact force receiving
portion) 1752Bn in the W42 direction, so that the movable member 1752B rotates
clockwise (in the BB direction) about the second supporting portion 1728Bk.
Then, by the second pressing surface (at-contact pressing portion) 1752Br being
brought into contact with the second pressed surface (at-contact pressed portion)
1751Be, the spacer 1751B is rotated about the first supporting portion 1728Bc in
the B2 direction (clockwise direction in the Figure). By this, the contact surface
1751Bc moves in the B2 direction with respect to the contacted surface 1715Bc,
and is separated from the contacted surface 1715Bc, so that the engagement
between the engaging portion 1715Bb and the separation holding portion 1751Bb
isreleased. The position of the spacer 1751B at this time is the permission
position (second position). By the movement of the spacer 1751B from the
restriction position to the permission position in this manner, the restriction on
the movement of the developing unit 1709B in the V2 direction (the direction
from the retracted position to the developing position) is released. Therefore,
the developing unit 1709B rotates in the V2 direction about the swing axis K until
the developing roller 1706 and the photosensitive drum 1704 come into contact
with each other, and the movement to the developing position (contacting
position) is completed.
[0980] Finally, the operation of changing from the development contact state
as shown in part (b) of Figure 164 to the spaced state shown in part (a) of Figure
164 will be described. From the contact state shown in part (b) of Figure 164,
the separation control member 196R (shown) moves in the W41 direction and
presses the first force receiving portion (retracting force receiving portion,
separating force receiving portion) 1752Bk in the W41 direction. By this, the
movable member 1752B is rotated about 1728Bk in the opposite direction
(counterclockwise direction) in the BB direction. Then, by the developing
frame pressing surface (at-separation pressing portion) 1752Bq urging the
pressed surface (at-separation pressed portion) 1728Bh of the development cover
member 1728B, the developing unit 1709B is rotated about the swing axis K in
the V2 (counterclockwise) direction. At this time, the spacer 1751B rotates in
the counterclockwise direction B1 about the first supporting portion 1728Bc by
the action of the tension spring 1753. By this, as shown in part (a) of Figure 164,
the contact surface 1751Bc of the spacer 1751B comes into contact with the contacted surface 1715Bc of the drum frame 1715B, and the engaging portion
1715Bb and the separation holding portion 1751Bb engage with each other, so
that the separated state of the developing unit 1709B is maintained.
[0981] The spacer 1751B of this embodiment has been described as having a
structure in which it can move between the first position and the second position
by receiving a force from the separation control member 196R of the apparatus
main assembly 170 by way of the movable member 1752B. However, the
spacer 1751B of this embodiment may be modified to have a movable structure
for receiving a force directly from the separation control member 196R of the
apparatus main assembly 170 without using the movable member as shown in the
Embodiment 9 to move between the first position and the second position.
[0982] According to the structure of this embodiment described above, the
same effects as those of Embodiments 1 and 9 can be provided.
[0983] Further, according to this embodiment, the spacer 1751B can be
disposed on a side opposite to the side having the second force receiving portion
(contact force receiving portion) 1752Bn and the first force receiving portion
(retracting force receiving portion, separating force receiving portion) 1752Bk
with respect to the swing axis K (or above the swing axis K).
<Embodiment 17>
[0984] In this embodiment, structures and operations different from those of
the above-described embodiment will be mainly described, and description of
similar structures and operations will be omitted. Further, for the structures
corresponding to those of the above-described embodiment, the same reference
numerals and characters are assigned, or the reference numerals in the first part is
changed while the reference numerals and characters in the second part are the
same. In this embodiment, in the process cartridge separation/contact mechanism, a structure will be described in which the separation is released by the moment when the spacer holds the separation is greater than the moment when the separation control member of the main assembly releases the separation by way of the movable member. In addition, the specific description will be made in the sections [Structure of separation/contact mechanism], [Contact operation of developing unit], and [Separation operation of developing unit].
Since the structures of other process cartridges are the same as those in the
Embodiment 1, they are omitted here. Further, since the non-drive-side has the
same structure as the drive-side and operates in the same manner, the description
of this embodiment will be described on the drive-side, and the description of the
non-drive-side will be omitted.
[Structure of separation/contact mechanism]
[0985] The structure in which the photosensitive drum 104 of the process cartridge 1800 and the developing roller 106 of the developing unit 1809 are
spaced from and contacted with each other in this embodiment will be described in detail. Part (a) of Figure 165 is a side view of the drive-side of the process
cartridge alone, and part (b) of Figure 165 shows a side view of the non-drive
side of the process cartridge alone. The drive-side has a separation/contact
mechanism 1850R, and the non-drive-side has a separation/contact mechanism
1850L. Figure 166 shows an assembly perspective view of the drive-side of the
developing unit 1809 including the separation/contact mechanism 1850R.
Figure 167 shows an assembly perspective view of the non-drive-side of the
developing unit 1809 including the separation/contact mechanism 1850L. Here, the details of the separation/contact mechanism 1850R on the drive-side will be
described. Since the separation/contact mechanism has almost the same
functions at the drive-side and the non-drive-side, R is added to the numerals of
each member for the drive-side. For the non-drive-side, the reference signs are the same as that of the drive-side, and L is added in place of R.
[0986] The separation/contact mechanism 1850R includes a spacer (separation holding member, restriction member), a movable member 1852R, and a tension
spring 1853, and the spacer includes a drum side engaging portion 1855R for
engagement with the developing side engaging portion 1854R and the developing side engaging portion 1854R.
[0987] Figure 168 is an enlarged view of the developing side engaging portion 1854R. The developing side engaging portion 1854R is provided on the
developing unit 1809. The developing side engaging portion 1854R is integrally
molded using resin material, together with the development cover member 1828.
Further, as viewed in the direction of Figure 165, the developing side engaging
portion 1854R is disposed such that an angle formed between a line connecting
the first force receiving surface 1852Rm (see Figure 173) and the swing axis K,
which will be described later, and the swing axis K, and a line connecting the
developing side engaging portion 1854R and the swing axis K is obtuse. Further, the developing side engaging portion 1854R is provided with a
developing side engaging claw 1854Ra which contacts the drum side engaging
portion 1855R in the separation state and a plate-shaped developing side holding
portion 1854Rb which connects the development cover member 1828 that is a
portion of the developing frame and the developing side engaging claw 1854Ra.
The developing side engaging claw 1854Ra has a developing side engaging
surface (contacting portion) 1854Rc which contacts the drum side engaging
portion 1855R in the separation state, and a developing side engagement return
surface 1854Rd which contacts the drum side engaging portion 1855R in the
process of transition from the contact state to the separation state. Forthe
reason which will be described hereinafter, it is preferable that the amount of
movement of the developing side spacer is large when the developing unit rotates about the swing axis K. Therefore, in this embodiment, the developing side spacer is provided at the position described above where the distance between the developing side spacer and the swing axis K can be made larger, but this feature is not restrictive.
[0988] In this embodiment, the developing side engaging portion 1854R is
provided on the development cover member 1828 which is a part of the
developing frame, but the present invention is not limited to such an example,
and the developing side engaging portion 1854R may be provided on another
member constituting a part of the developing frame.
[0989] Figure 169 shows an enlarged view of the drum side engaging portion
1855R. The drum side engaging portion 1855R is provided on the drum unit
1808 so as to engage with a developing-side engaging portion 1854R and hold
the developing unit 1809 in a spaced state. The drum side engaging portion
1855R is integrally molded with resin on the first drum frame portion 1815.
Further, the drum side engaging portion 1855R includes a drum side engaging
claw 1855Ra which engages with the developing-side engaging claw 1854Ra in
the separation state, and a plate-shaped drum side holding portion 1855Rb which
connects the first drum frame portion 1815, and the drum side engaging claw
1855Ra. Further, the drum side engaging claw 1855Ra includes a drum side
engaging surface (contacted portion) 1855Rc which contacts the developing-side
engaging surface 1854Rc in the separation state, and a drum side engagement
return surface 1854Rd which is contacted with the development side return
surface 1854Rd in the process of transition from the contact state to the
separation state. In this embodiment, the drum side engaging portion 1855R is
provided on the first drum frame portion 1815 which is a part of the drum frame,
but the present invention is not limited to such an example, and it may be
provided on another member constituting a part of the drum frame such as the drive-side cartridge cover member 1816.
[0990] Figure 170 is a perspective view in which the developing side engaging portion 1854R and the drum side engaging portion 1855R are engaged with each
other, that is, the developing unit 1809 is in the separated state. In the state in
which the developing side engaging portion 1854R and the drum side engaging portion 1855R are engaged with each other, the developing side holding portion
1854Rb is substantially parallel to the drum side holding portion 1855Rb. In
this state, it can be said that the developing side engaging portion 1854R and the
drum side engaging portion 1855R which constitute the spacer are in the
restriction positions (first position, engaging position), respectively.
[0991] As shown in Figure 166, the movable member 1852R is held rotatably about the third support portion 1828m by engaging the support receiving portion
1852Ra of the movable member 1852R with the third support portion 1828m.
Further, the movable member 1852R has a first force receiving surface (retracting
force receiving portion, separating force receiving portion) 1852Rm and a second force receiving surface (contact force receiving portion) 1852Rp (see Figure 171)
which can be engaged with the separation control member 196R (Figure 173)
mounted in the apparatus main assembly, and it includes a spring-hooked portion
1852Rs which engages with the tension spring 1853.
[0992] Further, as shown in Figure 165, the ends of the tension spring 1853
are engaged with the spring-hooked portion 1852Rs of the movable member 1852
and the spring-hooked portion 1828g of the development cover member 1828,
respectively. Therefore, the movable member 1852 is urged by the tension
spring 1853 in the upward direction CA about the third support portion 1828m as
the center of rotation.
[Contact operation of developing unit]
[0993] Next, referring to Figures 170 to 175, the operation of bringing the photosensitive drum 104 and the developing roller 106 into contact with each other by the separation/contact mechanism 1850R will be described in detail.
Figures 170, 173, and 177 are perspective views of the drive-side of the process
cartridge 1800. Figures 171, 174, 175, and 178 are side views of the process
cartridge 1800 mounted in the main assembly and the separation control member
which will be described hereinafter. In Figures 171 and 174, 175 and 178, parts
(a) is a side view of the drive-side, and parts (b) is a side view of the non-drive
side. Figures 172 and 176 are illustrations of the process cartridge 180 as
viewed from above along the directions perpendicular to the rotation axes M2 of
the developing roller 106 and Ul and U2. The Ul and U2 directions are
perpendicular to the rotation axis M2 of the developing roller 106 and are parallel
to the W41 and W42 directions.
[0994] In the structure of this embodiment, the development input coupling
132 receives a driving force from the image forming apparatus main assembly
170 in the direction of arrow V2 in Figure 171 to rotate the developing roller 106.
That is, the developing unit 1809 including the development input coupling 132
receives the torque in the arrow V2 direction from the image forming apparatus
main assembly 170. As shown in Figure 170, when the developing unit 1809 is
in a separated position and the developing side engaging portion 1854R and the
drum side engaging portion 1855R engage with each other, the developing unit
1809 is subjected to the above torque and the development pressure spring
described later, so that the developing unit 1809 is held in the separated position
against the urging force. Let Tr1 be the torque produced in the developing unit
by the torque from the apparatus main assembly 170 and the urging force of the
development pressure spring 134, in the V2 direction.
[0995] Similarly, to an Embodiment 1, the image forming apparatus main
assembly 170 of this embodiment includes the separation control member 196R and the cartridge pressing unit 121 corresponding to each process cartridge 1800 as described above. The separation control member 196R projects toward the process cartridge 1800 and has a space of 196Rd. Further, as in the
Embodiment 1 described above, the cartridge pressing unit 121 presses the
pressed surface 1852Rf of the movable member 1852R in interrelation with the
transition of the front door 111 from the open state to the closed state, and the
movable member 1852R moves downward. When it projects to a predetermined
position, a part of the movable member enters the space 196Rd of the separation
control member 196R, and the separation control member 196R, and the
separation control member 196R has a first force application surface 196Ra and a
second force application surface 196Rb which are opposed to the first force
receiving surface 1852Rm and the second force receiving surface 1852Rp of the
movable member 1852R with the space 196Rd therebetween. The first force
application surface 196Ra and the second force application surface 196Rb are
connected by way of a connecting portion 196Rc on the lower surface side of the
image forming apparatus main assembly 170. Further, the separation control
member 196R is supported by a control sheet metal (not shown) rotatably about
the rotation center 196Re. The separation control member 196R is normally
urged in the El direction by an urging spring (not shown), and it is restricted in
rotation in the rotational direction by a holder (not shown). Further, the control
sheet metal (not shown) is structured to be movable in the W41 and W42
directions from the home position by a control mechanism (not shown), and
therefore, the separation control member 196R is structured to be movable in the
W41 and W42 directions.
[0996] When the separation control member 196R moves in the W42 direction,
the second force application surface 196Ra of the separation control member
196R and the second force receiving surface 1852Rp of the movable member
1852R come into contact with each other, and the movable member 1852R
rotates in the direction CA about the support receiving portion 1852Ra until the
development cover pressing surface 1852Rr of the movable member 1852R
contacts the movable member locking portion 1828h provided on the
development cover member 1828. Further, when the separation control member
196R moves in the W42 direction, the movable member 1852R presses the
movable member locking portion 1828h of the development cover member 1828,
so that torque in the V2 direction is produced in the developing unit 1809. Let
this torque be Tr2, and the maximum value that can be generated by the main
assembly be Tr2MAX.
[0997] Next, referring to Figures 170 - 175, the description will be made as to
the forces produced in the developing side engaging portion 1854R and the drum
side engaging portion 1855R and the behavior of each component at the time
when the separation control member 196R described above moves in the W42
direction and a torque in the V2 direction is produced in the developing unit 1809.
First, a state in which the developing side engaging surface 1844Rc and the drum
side engaging surface 1855Rc are in contact with each other is an engaging state
(state in Figure 170). At this time, of the directions of the normal forces Ni and
between the developing side engaging surface 1854Rc and the drum side
engaging surface 1855Rc shown in Figures 170 and 171, the short side
component of the process cartridge is an axis U (Figure 170). Further, the
direction which is parallel to the axis U and in which the developing side
engaging portion 1854R moves when the developing unit 1809 rotates in the V2
direction is Ul, and the opposite direction is U2. When the developing unit
1809 receives torque in the V2 direction, the developing side engaging portion
1854R receives a force in the Ul direction. The direction from the non-drive
side to the drive-side parallel to the longitudinal direction of the process cartridge
1800 is the direction Ji, and the opposite direction is the direction J2. At this
time, as shown in Figure 172, of the normal force produced between the
developing side engaging surface 1854Rc and the drum side engaging surface
1855Rc, the normal force applied to the developing side engaging surface
1854Rc is the normal force NI, and the normal force applied to the drum side engaging surface 1854Rc is the normal force NI'. The normal force NI is
produced so that the developing side holding portion 1854Rb bends (elastically
deforms) so that the developing side engaging claw 1854Ra rotates
counterclockwise in Figure 172 about the fulcrum S. The normal force Ni'is
produced so that the drum side engaging claw 1855Ra bends (elastically deforms)
the drum side holding portion 1855Rb so as to rotate counterclockwise in Figure
172 about the fulcrum S'. That is, the developing side holding portion 1854Rb
bends in the Ji direction, and the drum side holding portion 1855Rb bends in the
J2 direction. Then, when the developing side engaging portion 1854R receives
a predetermined force in the U2 direction and moves in the U2 direction, the developing side holding portion 1854Rb and the drum side holding surface
1855Rb are bent until the developing side engaging surface 1854Rc and the drum
side engaging surface 1855Rc do not contact each other, by which the
engagement is broken. In this manner, the state in which the developing side
holding portion 1854Rb and the drum side holding portion 1855Rb are bent until
the developing side engaging surface 1854Rc and the drum side engaging surface
1855Rc do not contact with each other, can be said that the developing side
engaging portion 1854R and the drum side engaging portion 1855R constituting
the spacer is in the permission position (second position, disengaging position),
respectively. Further, the magnitude of the force required to disengage this
engagement is Fa.
[0998] After the engagement is released, the developing side engaging portion
1854R and the drum side engaging portion 1855R are flexed by restoring the
elastic deformation of the developing side holding portion 1854Rb and the drum
side engaging portion 1855Rb as shown in Figure 173, by which the deformation
is released. Then, the development side engagement return surface 1854Rd and
the drum side engagement return surface 1855Rd become in a state of facing each
other. At the same time, the developing unit 1809 rotates in the V2 direction
and moves to the contact position (development position) where the developing
roller 106 and the photosensitive drum 104 are in contact with each other (state in
Figure 174). At this time, the separation control member 196R has moved in the
W42 direction by a sufficient amount to disengage the developing side engaging
portion 1854R and the drum side engaging portion 1855R from each other, and
this position after the movement (Figure 174) is the first position. It is
preferable that the distance between the home position and the first position is
small because the main assembly mechanism for driving the separation control
member 196R can be downsized and the load can be reduced. Further, by
increasing the distance between the developing side engaging portion 1854R and
the swing axis K, the amount of movement of the developing side engaging
portion 1854R can be increased, and the amount of rotation of the developing unit
1809 required to disengage the developing side engaging portion 1854R and the
drum side engaging portion 1855R from each other can be reduced. After
moving to the first position, the separation control member 196R moves in the
W41 direction and returns to the home position. At this time, the movable
member 1852R is rotated in the CB direction by the tension spring 1853, and the
first pressing surface 1852Rq of the movable member 1852R and the first
pressing surface 1828k of the development cover member 1828 come into contact
with each other (state of Figure 175). By this, gaps T3 and T4 are formed, and
the separation control member 196R is placed at a position not acting on the movable member 1852R. The transition from the state of Figure 174 to the state of Figure 175 is performed without a delay.
[0999] As described above, in the structure of this embodiment, the movable
member 1852R is rotated by the movement of the separation control member
196R from the home position to the first position, and further, by the movable
member coming into contact with the development cover member to cause the
developing unit 1809, the developing side engaging portion 1854R and the drum
side engaging portion 1855R are moved to a permission position (second
position), thus these engagements are released. This makes it possible for the
developing unit 1809 to move from the spaced position to the contacting position
where the developing roller 106 and the photosensitive drum 104 are in contact
with each other. The position of the separation control member 196R in Figure
175 is the same as that in Figure 171.
[1000] Here, it will be described how the magnitudes of torque and force
produced in the process of transitioning the developing unit 1809 from the spaced
state to the contacted state are selected. As shown in Figure 171, let L be the
length of the line segment Y connecting the swing axis K and the contact points
between the developing side engaging surface 1854Rc and the drum side
engaging surface 1855Rc as the process cartridge 1800 is viewed from the
longitudinal drive-side, and let 0 be the angle formed by the line segment Y and
the above-mentioned direction U. When the relationship between Trl, Tr2, and
Fa described above is expressed using L and 0, the selection is made to satisfy the
following formulas (1) and (2):
Trl/Lsin0 < Fa .... (1)
(Tr1 + Tr2MAX)/LsinO > Fa .... (2)
[Separation operation of development unit]
[1001] Next, referring to Figures 171 and 175 to 178, the operation of moving the developing unit 1809 from the contact position to the separated position by the separation/contact mechanism 1850R will be described in detail.
[1002] The separation control member 196R in this embodiment is structured
to be movable from the home position in the W41 direction in Figure 175.When
the separation control member 196R moves in the W41 direction, the first force
application surface 196Rb and the first force receiving surface 1852Rm of the
movable member 1852R are brought into contact with each other, and the
movable member 1852R rotates in the CB direction about the support receiving
portion 1852Ra in the direction of CB. By the first pressing surface (not shown)
of the movable member 1852R contacting the first pressing surface (not shown)
of the development cover member 1828, the developing unit rotates in the VI
direction from the contact position. By the developing unit rotating in the VI
direction, the developing side engaging portion 1854R moves in the U2 direction,
and the developing side re-engagement assisting surfacel855Rd and the drum
side re-engagement assisting surface1854Rd are brought into contact with each
other. Further, by the separation control member 196R moving in the 41
direction, torque in the VI direction is generated in the developing unit 1809
about the swing axis K. The magnitude of the torque in the VI direction is Tr3,
and the maximum value which can be produced by the main assembly is
Tr3MAX. Since Tr3MAX is designed to satisfy Tr3MAX > Trl, the
developing unit 1809 rotates in the VI direction.
[1003] Next, referring to Figures 175 to 178, the description will be made as
to the forces to the developing side engaging portion 1854R and the drum side
engaging portion 1855R and the behavior of each component at the time when
the separation control member 196R described above moves in the W41 direction
and the developing unit 1809 rotates in the VI direction. When the developing
unit 1809 rotates in the V direction, the developing side engaging portion 1854R moves in the U2 direction. When the developing side engaging portion 1854R moves in the U2 direction, the developing side re-engagement assisting surface
1854Rd and the drum side re-engagement assisting surface 1855Rd are brought
into contact with each other. At this time, as shown in Figure 176, of the normal
force produced between the development side engagement return surface 1854Rd
and the drum side engagement return surface 1855Rd, the normal force applied to
the development side engagement return surface 1854Rd is the normal force N2,
and the normal force applied to the drum side engaging surface 1854Rd is the
normal force N2'. The normal force N2 is produced so that the developing side
holding portion 1854Rb bends (elastically deforms) so as to rotate the developing
side engaging claw 1854Ra counterclockwise in Figure 176 about the fulcrum S.
The normal force N2'is produced so that the drum side engaging claw 1855Ra
bends (elastically deforms) the drum side holding portion 1855Rb in the direction
of rotating counterclockwise in Figure 176 about the fulcrum S'. That is, the
developing side holding portion 1854Rb bends in the direction JI, and the drum
side holding portion 1855Rb bends in the direction J2. Then, when the
developing side engaging portion 1854R receives a predetermined force in the Ul
direction and moves in the U2 direction, the developing side holding portion
1854Rb and the developing side holding portion 1854Rb deform until the
developing side re-engagement assisting surface1854Rd and the drum side re
engagement assisting surface1855Rd become out of contact with each other. In
this state, it can be said that the developing side engaging portion 1854R and the
drum side engaging portion 1855R constituting the spacer are in the permission
positions (second position, disengagement position), respectively. The constant
force that the developing side engaging portion 1854R receives in the U2
direction is Fb.
[1004] Further, as the developing side engaging portion 1854R advances in the U2 direction, the bending of the developing side holding portion 1854Rb and the drum side engaging portion 1855Rb is released as shown in Figure 177, and the developing side engaging surface 1854Rc and a drum side engaging portion
1855Rc becomes in a state of facing each other. That is, the developing side
engaging portion 1854R and the drum side engaging portion 1855R are engaged.
At this time, by the movement of the separation control member 196R in the W41
direction until a gap is formed between the developing side engaging surface
1854Rc and the drum side engaging surface 1855Rc in the W42 direction, the
developing side engaging portion 1854R and the drum side engaging portion
1855R are securely engaged with each other. The position (Figure 178) of the
separation control member 196R after the movement is the second position.
After moving to the second position, the separation control member 196R moves
in the W42 direction and returns to the home position. At this time, the
developing unit 1809R is rotated in the V2 direction by the development pressure
spring 134, so that the developing side engaging surface 1854Rc and the drum
side engaging surface 1855Rc are brought into contact with each other (state in
Figure 171). At this time, it can be said that the developing side engaging
portion 1854R and the drum side engaging portion 1855R constituting the spacer
are at the restriction positions (first position, engaging position), respectively.
At this time, the gap T3 and the gap T4 are formed, and the separation control
member 196R is placed at a position of not acting on the movable member 1852R.
The transition from the state of Figure 178 to the state of Figure 171 is performed
without a delay.
[1005] As described above, in this embodiment, by the separation control
member 196R moving from the home position to the second position, the
developing side engaging portion 1854R moves in the U2 direction, and the
developing side engaging portion 1854R engages with the drum side engaging portion 1855R. Then, by the separation control member 196R returning from the second position to the home position, the developing side engaging surface
1854Rc and the drum side engaging surface 1855Rc are brought into contact with
each other, and the developing unit 1809 is maintained at the separated position
(retracted position) by the spacer (developing side engaging portion 1854R and
the developing side engaging portion 1854R)
[1006] Here, it will be described how the magnitudes of the torque and the
force generated in the process of transitioning from the contacted state to the
spaced state of the developing unit 1809 described above are determined. As
shown in Figure 175, Let L'be the length of the line segment Y'connecting the
swing axis K and the contact points between the developing side engaging
surface 1854Rc and the drum side engaging surface 1855Rc as the process
cartridge 1800 is viewed from the longitudinal drive-side, and let 0'be the angle
formed by the line segment Y' and the above-mentioned direction U. The
relationship between Trl, Tr3, and Fb are determined to satisfy the following,
using L' and 0':
(Tr3MAX-Trl)/L'sin 0' Fb . (3)
[1007] In this embodiment, when the developing unit 1809 is moved from the
retracted position (separation position) to the development position (contact
position) and when it is moved from the development position (contact position)
to the retracted position (separation position), both the side holding portion
1854Rb and the drum side holding portion 1855Rb elastically deform, but at least
one of them may be flexed (elastically deformed). Even when only one of the
developing side holding portion 1854Rb and the drum side holding portion
1855Rb bends (elastic deformation), it can be said that in this bent state, the
developing side engaging portion 1854R and the developing side engaging
portion 1854R constituting the spacer are in the permission position (second position, disengagement position).
[1008] Further, in this embodiment, the developing side engaging portion
1854R and the developing side engaging portion 1854R are structured to engage
and disengage by a snap-fit structure, but use may be made to a magnetic force
such as a magnet or a hook-and-loop fastener to engage and disengage them.
[1009] As described above, according to this embodiment, the same effects as
those of Examples 1 and 9 can be provided.
[1010] Further, in the Embodiment 1 and so on, it is necessary that the spacer
is be movably supported by either the developing frame or the drum frame, but in
this embodiment, the members constituting the spacer are bent (elastically
deformed), and therefore, the structure can be simplified accordingly. Further,
by integrally forming it on the developing frame and the members constituting
the drum frame as in this embodiment, the cost of the process cartridge 1800 can
be reduced by improving the assembling property and reducing the number of
parts.
<Embodiment 18>
[1011] Referring to Figures 179, 180, and 181, an embodiment of the process
cartridge and the image forming apparatus according to the eighteenth
embodiment of the present invention will be described. In this embodiment,
structures and operations different from those of the above-described
embodiment will be mainly described, and description of similar structures and
operations will be omitted. Further, for the structure corresponding to the
above-described embodiments, the same reference numerals and characters are
assigned, or the reference numerals in the first part is changed while the reference
numerals and characters in the second part are the same.
[1012] In this embodiment, the development cover member 2033 has a force receiving portion (first force receiving portion, contact force receiving portion)
2033e, and the spacer 2010 has a retracting force receiving portion (second force
receiving portion, separating force receiving portion) 2010m.
[1013] Figure 181 is a perspective view of the drive-side cartridge cover 2020
per se. The drive-side cartridge cover 2020 of this embodiment has a
deformation portion 2020f. The deformation portion 2020f comprises an arm
portion 2020e, a first contacted surface 2020c, and a third contacted surface
2020d. One end of the arm 2020e is fixed to the outer peripheral surface of the
cylindrical portion forming the supporting hole 2020b which supports the
photosensitive drum 4, and extends toward the supporting hole 2020a in which
the developing unit 9 is supported. A first contacted surface 2020c and a third
contacted surface 2020d are arranged at the other end. That is, the deformation
portion 2020f has a cantilever shape in which one end is fixed, and when the arm
2020e is deformed, the first contacted surface 2020c and the third contacted
surface 2020d on the other end side can move up and down substantially in the
direction of arrow Z2 in Figure 181 which is the direction of gravity. Here, as
shown in part (a) of Figure 181, the state in which the arm 2020e is not deformed
is a the maintaining state of the deformation portion 2020f. Further, as shown in
part (b) of Figure 181, the state in which the arm 2020e is deformed, and the first
contacted surface 2020c and the third contacted surface 2020d are moved from
the maintaining state in the direction of arrow Z2 in Figure (downward in the
direction of gravity) is the permission state of the deformation portion 2020f.
Details of the maintaining state and the permission state of the deformation
portion 2020f will be described in detail hereinafter.
[1014] Figures 179 and 180 are illustrations of the process cartridge P placed
in the second inner position inside the image forming apparatus main assembly
502 as in Figure 2 concerned with Embodiment 9 as viewed from the drive-side.
For better illustration, the drive-side cartridge cover is shown with omission of
the parts other than the arm 2020e of the deformation portion 2020f, the first
contacted surface 2020c, and the third contacted surface 2020d.
[1015] Part (a) of Figure 179 shows a state in which the spacer 2010 is in the permission position (second position), the developing unit 9 is in the developing position (contact position), and the separation control member 540 is in the home
position. In part (b) of Figure 179 and part (c) of Figure 179 show a state in the
process of the separation control member 540 moving from the home position to
the second position, the spacer 2010 moving from the permission position
(second position) to the regulated position (first position), and the developing unit
9 moving from the developing position (contact position) to the retracting
position (separation position). Part (d) of Figure 179 shows a state in which the
spacer 2010 is in the restriction position (first position), the developing unit 9 is
in the retracted position (separation position), and the separation control member
540 is in the home position.
[1016] The spacers (restriction member, spacing member, holding member) 2010 of this embodiment are similar to those of the Embodiment 9, and as shown
in part (a) of Figure 179, there are provided the supported hole (second contact
portion) 2010a and the projecting portion (holding portion) Part) 201Ob, the first
contact surface (contact part) 2010c. The supported hole (second contact
portion) 2010a is rotatably supported by a support portion 2033c, which is the
shaft of the development cover member 2033. Further, the spacer 2010 is urged
by a tension spring 530 (an urging means) in the direction of arrow B1 in part (a)
of Figure 179. Further, the spacer 2010 is provided with a retracting force
receiving portion (second force receiving portion, separating force receiving
portion) 2010m similar to Embodiment 10. The retracting force receiving
portion 2010m has a shape projecting in the direction of arrow Z2 in part (a) of
Figure 179.
[1017] The development cover member 2033 of this embodiment is fixed to
the developing unit 9 in the same manner as in the Embodiment 9. The force
receiving portion 2033e provided on the development cover member 2033 has a
shape projecting in the direction of arrow Z2 in part (a) of Figure 179, similarly
to the retracting force receiving portion 2010m.
[1018] The separation control member 540 of this embodiment is provided in
the image forming apparatus main assembly 502 as in the Embodiment 9. As
shown in part (a) of Figure 179, the force receiving portion 2033e, the separation
control member 540, and the retracting force receiving portion 2010m are
arranged in this order in the arrow W51 in part (a) of Figure 179. Similarly to
Embodiment 9, the separation control member 540 is movable. Further, the
separation control member 540 is structured to be movable between the first
position and the second position to the home position where the force receiving
portion 2033e and the retracting force receiving portion 2010m do not contact
with each other, between the first position and the second position.
[Separation operation]
[1019] Referring first to Figure 179, the operation of moving the developing
unit 9 from the developing position (contact position) to the retracted position
(separation position) will be described. When the separation control member
540 moves in the arrow W51 direction in part (a) of Figure 179 which is the
direction toward the second position from the home position shown in part (a) of
Figure 179, the first force application surface 540b and the retracting force
receiving portions 201Om of the spacer 2010 are brought into contact with each
other so that the first force application surface 540b presses the portion 201Om.
The spacer 2010 of which the retracting force receiving portion 2010m is pressed
presses the third contacted surface 2020d of the deformation portion 2020f at the third contact surface 2010k in the direction of the arrow N6 in part (b) of Figure
179, while rotating in the direction of the arrow B1 in part (b) of Figure 179,
which is the direction from the permission position to the restriction position.
Then, in the deformation portion 2020f pressed at the third contacted surface
2020d, the arm 2020e is deformed, and the first contacted surface 2020c and the
third contacted surface 2020d are moved in the direction of the Z2 in part (b) of
Figure 179, and it changes from the maintaining state to the permission state in
which the cantilever is bent (elastically deformed) (state in part (b) of Figure 179).
As shown in part (b) of Figure 179, when the deformed portion changes from the
maintaining state to the permission state, the developing unit 9 rotates in the
direction of the arrow VI in part (b) of Figure 179 and can move from the
developed position to the retracted position.
[1020] Further, as shown in part (c) of Figure 179, when the separation control
member 540 moves to the second position, the spacer 2010 and the deformation
portion 2020f are separated from each other, by which the deformation portion
2020f returns from the permission state to the maintaining state by the elastic
force.
[1021] Further, when the separation control member 540 moves from the
second position in the arrow W52 direction in part (c) of Figure 179 back to the
home position again, the separation control member 540 and the spacer 2010 are
separated from each other, and the developing unit 9 is rotated in the direction of
the arrow V2 in part (c) of Figure 179 by the driving force received by the
development coupling member 74. Then, the first contact surface (contact
portion) 201Oc of the spacer 2010 placed at the restriction position (first position)
and the first contact surface (contact portion) 2020c of the deformation portion
2020f contact with each other, and the attitude of the developing unit 9 is
maintained at the retracted position (separated position) (state shown in part (d) of Figure 179).
[1022] As shown in part (d) of Figure 179, since the separation control
member 540 placed at the home position is separated from the spacer 2010, the
separation control member 540 is not loaded by the developing unit 9.
[1023] As described above, the developing unit 9 can be moved from the
development position (contact position) to the retracted position (separation
position) by the operation of the separation control member 540 moving from the
home position to the second position and returning to the home position again.
[Contact operation]
[1024] Next, referring to Figure 180, the operation of moving the developing
unit 9 from the retracted position (separation position) to the developing position
(contact position) will be described.
[1025] Part (a) of Figure 180 shows a state in which the spacer 2010 is in the
restriction position (first position), the developing unit 9 is in the retracted
position (separation position), and the separation control member 540 is in the
home position. Part (b) of Figures 180 and 180 (c) show a state in which the
separation control member 540 is moving from the home position toward the first
position and the developing unit 9 is moving from the retracted position to the
developing position. Part (d) of Figure 180 shows a state in which the spacer
2010 is in the permission position (second position), the developing unit 9 is in
the developing position (contact position), and the separation control member 540
is in the home position.
[1026] When the separation control member 540 moves from the home
position in the arrow W52 direction in part (a) of Figure 180, which is the first
position direction, the second force application surface 540c of the separation
control member 540 and the force receiving portion 2033e of the development
cover member 2033 are brought into contact with each other (state in part (b) of
Figure 180). Further, when the separation control member 540 moves in the
first position direction, the force exerted by the first contact surface 2010c on the
first contacted surface 2020c in the direction of arrow N7 in part (b) of Figure
180 increases. Then, the arm 2020e is deformed by this force, and the first
contacted surface 2020c and the third contacted surface 2020d move in the
direction of arrow Z2 in part (b) of Figure 180. That is, the deformation portion
2020f bends (elastically deforms) and shifts from the maintaining state to the
permission state (State of part (c) of Figure 180).
[1027] When the separation control member 540 further moves in the arrow
W52 direction in part (c) of Figure 180 from the state shown in part (c) of Figure
180, the developing unit 9 rotates in the direction of the arrow V2 in part (c) of
Figure 180 and moves from the retracted position to the developed position by a
force received from the second force application surface 540c by the force
receiving portion 2033e. At this time, while the third contacted surface 2020d is
in contact with the third contact surface 2010k of the spacer 2010, the
deformation portion 2020f returns from the permission state to the maintaining
state by the elastic force. At the same time, the spacer 2010, which receives a
reaction force on the third contact surface 2010k, rotates in the direction of arrow
B2 in part (c) of Figure 180 relative to the developing unit 9, and the phase of the
spacer 2010 changes from the restriction position (first position) to the
permissible position (second position).
[1028] The separation control member 540 moves from the home position to
the second position, moves the attitude of the developing unit 9 from the retracted
position to the developing position, and then moves in the arrow W52 direction in
part (d) of Figure 180 to return to the home position again.
[1029] As shown in part (d) of Figure 180, the separation control member 540
placed at the home position is separated from the force receiving portion 2033e, and therefore, the separation control member 540 is not loaded by the developing unit 9.
[1030] As described above, the developing unit 9 can be moved from the
retracted position to the developed position by the operation of the separation
control member 540 moving from the home position to the first position and
returning to the home position.
[1031] Further, in this embodiment, the deformation portion 2020f has been
described as having a beam shape, but the present invention is not limited to such
an example. The structure may be such that a shape different from the beam
shape may be deformed, so that the first contacted surface 2020c and the third
contacted surface 2020d are movable between the permission state in which the
developing unit 9 can rotate, the maintaining state in which the attitude thereof is
maintained with the developing unit 9 being in the retracted position and the
developing position. The deformation portion 2020f is structured to move
between the permission state and the maintaining state relative to the drive-side
cartridge cover 2020 so that the spacer 2010 can move between the restriction
position and the permission position. Therefore, it can be said that the
deformation portion 2020f is a spacer on the drum unit side.
[1032] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
[1033] Further, in this embodiment, the development cover member 2033
fixed to the developing unit 9 is provided with the force receiving portion 2033e,
and the spacer 2010 is provided with the retracting force receiving portion 2010m,
by which the attitude of the developing unit 9 can be controlled stably.
<Embodiment 19>
[1034] Referring to Figure 182, an embodiment of the process cartridge and the image forming apparatus according to the nineteenth embodiment of the present invention will be described. In this embodiment, structures and operations different from those of the above-described embodiment will be mainly described, and description of similar structures and operations will be omitted. For the structure corresponding to that in the above-described embodiment, the same reference numerals and characters are assigned, or the reference numerals in the first part is changed while the reference numerals and characters in the second part are the same.
[1035] In this embodiment, the force receiving portion (first force receiving
portion, contact force receiving portion) 2133e and the retracting force receiving
portion (second force receiving portion, separating force receiving portion)
2133m are provided on the cover member 2133 fixed to the developing unit 9.
[1036] Further, the drive-side cartridge cover 2020 of this embodiment is the
same as that of the 18th embodiment, and has a structure having a deformation
portion 2020f.
[1037] Figure 182 is a view of the process cartridge P placed at the second
inner position inside the image forming apparatus main assembly 502 as viewed
from the drive-side, as in Figure 2 of the Embodiment 9. For better illustration,
the drive-side cartridge cover 2020 is shown with the parts being omitted with the
exception of the arm 2020e of the deformation portion 2020f, the first contacted
surface 2020c, and the third contacted surface 2020d.
[1038] Part (a) of Figure 182 shows a state in which the spacer 2110 is in the
permission position (second position), the developing unit 9 is in the developing
position (contact position), and the separation control member 540 is in the home
position. Part (b) of Figure 182 and part (c) of Figure 182, shows the state in
which the separation control member 540 is moving from the home position to
the second position, and the developing unit 9 is moving from the developing position (contact position) to the retracting position (separation position). Part
(d) of Figure 182 shows a state in which the spacer 2110 is in the restriction
position (first position), the developing unit 9 is in the retracted position
(separation position), and the separation control member 540 is in the home
position.
[1039] As shown in part (a) of Figure 182, the spacer (restriction member,
holding member, separation holding member) 2110 of this embodiment includes
a supported hole (second contact portion) 2110a, a projecting portion (holding
portion) 211Ob, and a first contact surface (contact part) 211Oc, as in the
Embodiment9. The supported hole 2110a is rotatably supported by the support
portion 2133c, which is the shaft of the development cover member 2133, and the
spacer 2110 is urged in the direction of the arrow B1 in part (a) of Figure 182 by
the tension spring 530 (biasing means).
[1040] Further, the development cover member 2133 of this embodiment is
fixed to the developing unit 9 in the same manner as in the Embodiment 9. The
development cover member is provided with the force receiving portion 2133e
which is the same as in embodiment 21, and further is provided further with a
retracting force receiving portion 2133m. Similar to the force receiving portion
2133e, the retracting force receiving portion 2133m has a shape projecting in the
direction of arrow Z2 in part (a) of Figure 182.
[1041] The separation control member 540 of this embodiment is included in
the image forming apparatus main assembly 502 as in the Embodiment 9. As
shown in part (a) of Figure 182, the separation control member 540 is disposed
between the projecting force receiving portion 2133e and the retracting force
receiving portion 2133m (in the arrows W51 and W52 directions in part (a) of
Figure 182).
[1042] Similarly to the Embodiment 9, the separation control member 540 can move between the first position and the second position. Further, the separation control member 540 is structured to be movable to the position not contacting the force receiving portion 2133e and the retracting force receiving portion 2133m, between the first position and the second position to a home position.
[Separation operation]
[1043] Referring to Figure 182, the operation of moving the developing unit 9
from the development position (contact position) to the retracted position
(separation position) will be described.
[1044] When the separation control member 540 moves from the home
position shown in part (a) of Figure 182 to the arrow W51 direction in part (a) of
Figure 182, which is the second position direction, the first force application
surface 540b and the retracting force receiving portion 2133m come into contact
with each other, and the first force application surface 540b presses the retracting
force receiving portion 2133m. When the retracting force receiving portion
2133m is pressed, the developing unit 9 rotates from the developing position to
the retracting position in the direction of the arrow VI in part (a) of Figure 182.
At this time, the attitude of the spacer 2110 is restricted by the contact between
the third contact surface 2110k of the spacer 2110 and the third contacted surface
2020d.
[1045] Further, when the separation control member 540 moves in the arrow
W51 direction in part (b) of Figure 182 to the second position, the third contact
surface 2110k and the third contacted surface 2020d are separated from each
other, and the spacer 2110 is rotated from the permission position (second
position) to the restriction position (first position) by the urging force of a tension
spring 530 (State of part (c) of Figure 182). When the separation control
member 540 moves from the second position in the arrow W52 direction in part
(c) of Figure 182 and returns to the home position again, the developing unit 9 is rotated in the V2 direction by the driving force received by the development coupling member as shown by the arrow in part (c) of Figure 182. Then, the first contact surface (contact portion) 211Oc of the spacer 2110 located at the restriction position and the first contacted surface (contacted portion) 2020c of the deformation portion 2020f which is in the maintaining state come into contact with each other, and the attitude of the developing unit 9 is maintained in the retracted position (state shown in part (d) of Figure 182).
[1046] As shown in part (d) of Figure 182, since the separation control member 540 located at the home position is separated from the spacer 2110, the
separation control member 540 is not loaded by the developing unit 9.
[1047] In the manner described above, the developing unit 9 can be moved from the development position to the retracted position by the operation of the
separation control member 540 moving from the home position to the second
position and returning to the home position again.
[1048] In this embodiment, when the developing unit 9 moves from the developing position to the retracted position, the deformation portion 2020f does
not change from the maintaining state to the permission state. On the other hand, when the developing unit 9 moves from the retracted position to the developing
position, the deformation portion 2020f is changed to the maintaining state and
the permission state as in above-described Embodiment 18.
[1049] In this embodiment, the deformation portion 2020f has been described as having a beam shape, but the present invention is not limited to such an
example. The structure may be such that the shape different from the beam
shape is deformed, and the first contacted surface 2020c and the third contacted
surface 2020d are movable between an permission state in which the developing
unit 9 can rotate, and the maintaining state in which the attitude is maintained
with the developing unit 9 being in the retracted position and the developing position.
[1050] The deformation portion 2020f is structured to move between the
permission state and the maintaining state relative to the drive-side cartridge
cover 2020 so that the spacer can move between the restriction position and the
permission position. Therefore, it can be said that the deformation portion
2020f is a spacer on the drum unit side.
[1051] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 1 and 9 can be provided.
[1052] Further, in this embodiment, the attitude of the developing unit 9 can
be stably controlled with the structure in which the development cover member
2133 fixed to the developing unit 9 has the force receiving portion (first force
receiving portion, contact force receiving portion) 2133e and the retracting force
receiving portion (second force receiving portion, separating force) 2133m.
<Embodiment 20>
[1053] Referring to Figures 183 to 191, Embodiments of the process cartridge
and the image forming apparatus according to embodiment 22 of the present
invention will be described.
[1054] In this embodiment, structures and operations different from those of
the above-described embodiment will be mainly described, and description of
similar structures and operations will be omitted. For the structure
corresponding to that in the above-described embodiment, the same reference
numerals and characters are assigned, or the reference numerals in the first part is
changed while the reference numerals and characters in the second part are the
same.
[Constituent parts]
[1055] First, the structure of each component in this embodiment will be described.
[1056] The lever 22510 is provided with a force receiving portion (first force receiving portion, contact force receiving portion) 22510e and a retracting force
receiving portion (second force receiving portion, separating force receiving
portion)22510a. Further, the lever 22510 is supported, at the supported hole 2251Od thereof, by a supporting shaft 2233b provided in the development cover
member 2233 which is a portion of the development frame and is rotatably
mounted. Further, the lever 22510 is provided with an abutting portion 22510b.
[1057] A stopper portion 2233a is integrally provided on the development cover member 2233. By abutting against the abutting portion 22510b, the
clockwise (V4 direction) and counterclockwise (V3 direction) rotation of the
lever 22510 is restricted.
[Spring]
[1058] A tension spring (separation direction urging member) 22541 and a tension spring (contact direction urging member) 22542 are mounted between the drum unit 2208 and the developing unit 2209. The hook portion 22541b on one
end side of the tension spring is mounted to the boss 2208b which is a portion of
the drum frame of the drum unit 2208, and the other end hook portion 22541a of
the tension spring 22541 is mounted to a boss 2209a which is a portion of the
developing frame of the developing unit 2209. A counterclockwise moment (in
the VI direction) about the swing axis K acts on the developing unit 2209 by the
tension spring 22541. Next, the tension spring 22542 will be described.
[1059] One end side hook portion 22542b of the tension spring 22542 is mounted to a boss 2208c which is a portion of the drum frame of the drum unit
2208. The other end hook portion 22542a of the tension spring 22542 is
mounted to a shaft member 22511 which can slide in the oblong round hole
22510c of the lever 22510. The shaft member 22511 is constrained from moving in a direction parallel to the direction of the developing roller rotation axis M2, and can slide only in the longitudinal direction of the oblong round hole
22510c. By this tension spring 22542, it is possible to apply a clockwise
moment (in the V2 direction) about the swing axis K to the developing unit 2209.
[Outline of operation]
[1060] Next, referring to part (a) of Figure 184 and part (b) of Figure 184, the
outline of the operation of this embodiment will be described. In the state of
part (a) of Figure 184, the developing unit 2209 is in the retracted position
(separated position) with respect to the drum unit 2208 by the urging force of the
tension spring 22541, in the free state of the process cartridge. Atthistime,the
moment M2'produced by the tension spring 22542 is smaller than the moment
M1' produced by the tension spring 22541. Further, the abutting portion 2209b
of the developing unit 2209 and the abutting portion 2208d of the drum unit 2208
are in contact with each other, and the rotation of the developing unit 2209 in the
arrow VI direction is restricted. Therefore, it can be said that the drum unit
2208 stably maintains the developing unit 2209 in the retracted position
(separated position). At this time, it is assumed that the lever 22510 and the
tension spring 22542 constituting the holding portion are in the first positions for
the drum unit 2208 to stably hold the developing unit in the retracted position
(separation position).
[1061] As having been described in Embodiment 1, the separation control
member 22540 moves from the home position to the first position (arrow W52
direction) and returns to the home position. By this, the lever 22510 rotates
about the rotation center 2251d to move to the second position (part (b) of
Figure 183). By this operation, the relative position of the other end hook
22542a of the tension spring 22542 to the oblong round hole 2251Oc of the shaft
member 2251 changes, such that the distance from the swing axis center K to the shaft member 22511 increases (LI and L2'). At this time, the moment M2 produced by the tension spring 22542 is larger than the moment M1 produced by the tension spring 22541. By this, the developing unit 2209 moves from the retracted position (part (a) of Figure 184) to the developing position (part (b) of
Figure 184). At this time, the developing roller 106 and the photosensitive
member drum 104 are in contact with each other, and the rotation of the
developing unit 2209 in the arrow V2 direction is restricted. Therefore, it can be
said that the drum unit 2208 stably maintains the developing unit 2209 at the
developing position (contact position). At this time, it is assumed that the lever
22510 and the tension spring constituting the holding portion are in the second
positions for the drum unit 2208 to stably maintains the developing unit 2209 at
the developing position (contact position).
[Contact operation]
[1062] Next, referring to Figures 185 to 187, the details of the operation of the
developing unit 2209 moving from the retracted position (separated position) to
the developing position (contact position) will be described. First, as shown in
part (a) of Figure 185, the separation control member 22540 moves in the arrow
W52 direction. Next, the separation control member 22540 further moves in the
arrow W52 direction while contacting and pressing the force receiving portion
(first force receiving portion, contact force receiving portion) 2251Oe, and the
developing unit 2209 is rotated about the swing axis K in the direction of arrow
V2 (direction from the retracted position to the developed position). Then, by
contacting of the developing roller 106 to the photosensitive drum 104, the
position of the developing unit 2209 is determined at the developing position, and
the rotation is stopped.
[1063] Further, when the separation control member 22540 continues to move
in the arrow W52 direction, and the lever 22510 is rotated in the V4 direction
(from the first position to the second position) about the rotation center 2251Od
the lever 22510 with the movement of the force receiving portion 22510e in the
direction of W52. When the angle (0 shown in part (a) of Figure 186) formed
by the central axis of the oblong round hole 2251Oc and the coil central axis of
the tension spring 22542 exceeds 900, The shaft member 22511 connected to the
other end of the tension spring 22542 slides in the oblong round hole 2251Oc of
the lever 22510 in the arrow W53 direction. Then, when the line connecting the
center of the shaft member 22511 and the center of the boss 2208c exceeds the
neutral point (in this case, the rotation center 251Od), the lever is rotated in the
arrow V4 direction by the tensile force of the tension spring 22542. Finally, as
shown in part (b) of Figure 186, the first abutting portion 2251Ob1 of the abutting
portion 22510b of the lever 22510 abuts against the first stopper portion 2233al
of the stopper portion 2233a. By this, the rotation of the lever 22510 in the
arrow V4 direction is stopped, and the position is determined at the second
position. Further, the position of the shaft member 22511 is determined by
abutting at the end portion 2251Of of the oblong round hole 2251Oc, and the
tension force of the tension spring 22542 acts on the developing unit 2209.
Although the details will be described hereinafter, in this state, as to the rotational
moment around the rotation axis K, the rotational moment M2 produced by the
tension spring 22542 is larger than the rotational moment M1 produced by the
tension spring 22541, and therefore, the developing unit 2209 can be maintained
at the developing position (contact position).
[1064] Next, the separation control member 22540 moves in the arrow W51
direction. And, it returns to the position (home position) in which the separation
control member and the lever 22510 are not in contact with each other, and the
movement of the developing unit 2209 from the retracted position to the
developing position is completed.
[Separation operation]
[1065] Next, the operation from the developing position (contact position) to
the retracting position (separation position) will be described. As shown in part
(a) of Figure 188, when the developing unit is in the developing position, the
separation control member 22540 starts moving in the direction of arrow W51.
[1066] Then, the first force application surface 22540b of the control member
22540 abuts and presses the retracting force receiving portion (second force
receiving portion, separating force receiving portion) 22510a of the lever 22510,
by which the developing unit 2209 starts to rotate in the arrow VI direction
(direction from the development position to the retracted position). When the
abutting portion 2209b of the developing unit 2209 and the abutting portion
2208d of the drum unit 2208 come into contact with each other as shown in part
(b) of Figure 188, the rotation of the developing unit 2209 in the arrow VI
direction is restricted, and the position of the developing unit is determined at the
retracted position.
[1067] Then, as shown in part (a) of Figure 189, when the separation control
member 22510 continues further to move in the arrow W51 direction, the
retracting force receiving portion 2251Oa is further pressed and the lever 22510 is
rotated in the direction of the arrow V3 (direction from the second position to the
first position) about the rotation center 22510d. Then, the shaft member 2251 to
which the other end hook 22542a is connected slides in the oblong round hole
22510c in the arrow W53 direction. Further, when the separation control
member 22510 moves in the arrow W51 direction, the line connecting the
position of the tension spring 22542 with the center of the shaft member 22511
and the center of the boss 2208c goes beyond the neutral point (in this case, the
rotation center 2510d). As shown in part (b) of Figure 189, after passing
through the neutral point, the shaft member 22511 further moves in the oblong round hole 2251Oc in the arrow W53 direction by the tension force of the tension spring 22542. When the shaft member 22511 abuts to the upper end of the oblong round hole 2251Oc so that the movement in the W53 direction is stopped, the lever 22510 is rotated in the arrow V3 direction by the force of the tension spring 22542.
[1068] Then, as shown in part (a) of Figure 190, the lever 22510 abuts finally
against the second stopper portion 2233a2 of the stopper portion 2233a at the
second abutting portion 22510b2 of the abutting portion 22510b. Bythis,the
rotation of the lever 22510 relative to the development cover member 2233 is
stopped, and the position is determined at the first position. Although the details
will be described hereinafter, in this state, the distance between the tension spring
22542 and the swing axis K is shorter than the distance between the tension
spring 22541 and the swing axis K, so that the rotation moment M2'in the arrow
V2 direction is less than the moment at the developed position. Then, since it is
smaller than the rotational moment M1'in the V Idirection generated by the
tension spring 22541, it is possible to maintain the attitude of the retracted
position (separation position). Then, as shown in part (b) of Figure 190, the
separation control member moves in the arrow W52 direction, returns to a
position (home position) not in contact with the separation control member 22540
and the lever 22510, and the movement operation to the retracted position is
completed.
[Relationship of forces]
[1069] Next, referring to part (a) of Figure 191 and Figure 191 (b), the
relationship between the forces acting on the developing unit when the
developing unit 2209 is in the developing position and the retracted position will
be described. Part (a) of Figure 191 is an illustration showing the force acting
on the developing unit 2209 at the developing position, and part (b) of Figure 191 is an illustration showing the force acting on the developing unit 2209 at the retracted position. Here, the moments acting in the directions of arrows VI and
V2 at the development position are Mi and M2, respectively, and the moments
acting in the directions of arrows VI and V2 around the swing axis K at the
retracted position are Mi'and M2', respectively. And, the distance from the
swing center K to the boss 2209a at the developing position is LI, the distance
from the swing center K to the shaft member 22511 is L2, and the distance from
the swing axis K to the shaft member 22511 at the retracted position is L2'.
[1070] First, referring to part (a) of Figure 191, the relationship of forces at the
developing position will be described. When the balance of moments is
considered about the swing axis K, the moment Mi generated by the tension
spring 22541 is expressed by Mi = Fi • LI. The moment M2 produced by the
tension spring 22542 is expressed by M2 = F2 • L2. The distance between the
rotation center K and the boss 2209a at the development position is L1, and the
distance between the rotation center K and the boss 2208c and Fi is L2. Further,
of the forces received by the boss 2209a from the tension spring 22541, the force
in a tangential direction of a circle passing through the boss 2209a about the
rotation center K is Fi, and of the force received by the boss 2208c from the
tension spring 22542, the force in a tangential direction of a circle passing
through the boss 2208c about the rotation center K is F2.
[1071] Here, in order to maintain the attitude (stable holding) at the
developing position, M2 and Miare set so as to satisfy the following formula (1).
M2 > MI ... (1)
[1072] Next, referring to part (b) of Figure 191, the relationship of forces at
the retracted position will be described.
[1073] Assuming that the moments acting in the directions of the arrows VI
and V2 are Mi'and M2', respectively, the moment produced by the tension spring
22541 is, when considering the balance of the moments about the swing axis K as
described above, satisfy Ml'= Fl' • L1. The moment M2' produced by the
tension spring 22542 is expressed by M2'= F2' • L2'. Here, the distance
between the rotation center K and the boss 2209a at the retracted position is Li',
and the distance between the rotation center K and the boss 2208c and Fl is L2'.
Further, of the forces received by the boss 2209a from the tension spring 22541,
the force in the tangential direction of a circle passing through the boss 2209a
about the rotation center K is Fl', and the force received by the boss 2208c from
the tension spring 22542 in the tangential direction of a circle passing through the
boss 2208c about the rotation center K is F2'.
[1074] Here, in order to maintain the attitude (stable holding) at the retracted
position, M1'and M2' are set so as to satisfy the following formula (2).
M2'< Ml' ...... (2)
Further, in the retracted position, the urging force F2'of the tension spring
22542 may be 0 (zero) because the equation 2 may be satisfied.
[Holding mechanism]
[1075] In the above-described embodiment, the structure for the drum unit
2208 to stably hold the developing unit 2209 at the retracted position and the
developing position is the lever22510 and the tension spring 22542 capable of
taking the first position and the second position, respectively. However, it is
also possible to see the structure of this embodiment as follows. That is, as a
holding mechanism in which the drum unit 2208 stably holds the developing unit
2209 at the retracted position and the developing position, at least the lever 22510,
the tension spring 22542, the boss 2208c, the shaft member 22511, the tension
spring 22541, the boss 2208b, and the boss 2209a maybe considered. Inthis
case, it can be said that when the lever 22510 and the tension spring 22542 are in
the first positions and the developing unit 2209 is in the retracted position, the holding mechanism is in the first state, and when the lever 22510 and the tension spring 22542 are in the second positions and the developing unit 2209 is in the developing position, the holding mechanism is in the second state.
[1076] As described above, in this embodiment, the developing unit 2209 is
constantly urged by the tension spring 22541 in the direction from the developing
position to the retracted position. Then, by changing the positions of the lever
22510 and the tension spring 22542 as the holding portion, the magnitude of the
moment produced in the developing unit 2209 by the urging force of the tension
spring 22542 is changed, and the movement between the developing position and
the retracting position is carried out. With such a structure as well, the drum
unit can stably hold the developing unit at each of the developing position and the
retracting position. Therefore, the same effect as in Embodiments 1 and 9 can
be provided.
[1077] Further, in this embodiment, the developing unit 2209 is urged toward
the retracted position by the moment of the tension spring 22541 even when it is
in the developing position, but the developing roller 106 is urged toward the
photosensitive drum 104 by the moment of the tension spring 22542 so that the
position of the developing unit 2209 can be determined. Therefore, the
developing roller 106 can be contacted with the photosensitive drum 104 with an
appropriate pressure.
<Embodiment 21>
[1078] Referring to Figures 192 to 194, a process cartridge and an image
forming apparatus according to Embodiment 21 of the present invention will be
described. In this embodiment, structures and operations different from those of
the above-described embodiment will be mainly described, and description of
similar structures and operations will be omitted. For the structure corresponding to that in the above-described embodiments, the same reference numerals and characters are assigned, or the reference numerals in the first part is changed while the reference numerals and characters in the second part are the same.
[1079] Figures 192 and 194 are illustrations of the process cartridge P as viewed from the drive-side inside the image forming apparatus main assembly
502. An urging member 2410 a holding portion that can be moved between a
development holding position (first position) for the developing unit 9 to stably
hold at the developing position and a separation holding position (second
position) for stably holding the developing unit 9 at the retracted position.
[1080] In this embodiment, the urging member (restriction member, holding member, separation holding member) 2410 is a compression coil spring provided
between the drum unit 8 and the developing unit 9. One end of the urging
member 2410 is an end coil shape portion 241Ob, and the other end is a hook
shape portion 2410c.
[1081] The drum unit 8 is provided with an urging member supporting portion 2481 as a portion of a drum frame for supporting the end coil shape portion
2410b which is one end portion of the urging member 2410. Theurging
member supporting portion 2484 includes an urging member seating portion
2481b for receiving the end coil shape portion 241Ob and an urging member outer
diameter supporting portion 2481c for supporting the coil portion outer diameter
side of the urging member 2410. One end side of the urging member is
supported by the urging member seating portion 2481b and the urging member
outer diameter supporting portion 2481c, so that the urging member seating
portion 2481b is supported substantially linearly in the normal line direction.
[1082] Here, a straight line L80 is a line normal to the urging member seating portion 2484b on which the end coil shape portion 2410b which is one end of the urging member 2410 is seated, and passes through the swing axis K of the developing unit 9.
[1083] Next, the development cover member (a portion of the developing
frame) 2433 of the developing unit 9 is provided with a spring-hooked portion
2433c having a cylindrical shape for supporting the hook shape portion 2410c.
One end side of the urging member 2410 is supported by the drum unit 8, and the
hook shape portion 241c on the other end side is supported by engaging with the
spring-hooked portion 2433c of the developing unit 9. The urging member
2410 is a compression coil spring, and is compressed between the drum unit 8
and the developing unit 9.
[1084] In this embodiment, the development cover member 2433 is provided
with a force receiving portion (first force receiving portion, contact force
receiving portion) 2433e for engaging with the separation control member 2440
provided in the image forming apparatus main assembly 502, and a retracting
force receiving portion(second force receiving portion, separating force receiving
portion) 2433m.
[1085] The separation control member 2440 is movable between a first
position for moving the urging member 2410 to the contact holding position and
a second position for moving the urging member 2410 to the separation holding
position. Further, the separation control member 2440 is structured to be
movable to a home position where the separation control member 2440 does not
contact the force receiving portion 2433e and the retracting force receiving
portion 2433m, between the first position and the second position.
[1086] Next, the description will be made as to behavior in which the urging
member 2410 moves between the contact holding position (second position) for
holding the developing unit 9 at the developing position (contacting position) and
the separation holding position (first position) for holding the developing unit 9 at the retracting position (separating position). In part (a) of Figure 192, the developing unit 9 is in the developing position, and the separation control member 2440 is in the first position. In part (c) of Figure 192, the developing unit 9 is in the separated position, and the separation control member 2440 is in the second position. Part (b) of Figure 192 shows a state in which the developing unit 9 is in the process of switching from the developing position shown in part (a) of Figure 192 to the spaced position shown in part (c) of Figure
192. In part (d) of Figure 192, the developing unit 9 is in the spaced position,
and the separation control member 2440 is in the home position.
[1087] In part (a) of Figure 192, the developing unit 9 is in the developing
position, and the spring-hooked portion 2433c is placed on the downstream side
in the arrow V2 direction from the straight line L80. When the separation
control member 2440 moves from the first position in the W51 direction, the first
force application surface 2440b and the retracting force receiving portion 2433m
are brought into contact with each other, and the developing unit is rotated about
the swing axis K in the VI direction in part (b) of Figure 192.
[1088] In part (b) of Figure 192, as a result of the developing unit 9 rotating in
the VI direction from part (a) of Figure 192, the spring-hooked portion 2433c is
placed on the straight line L80.
[1089] Further, when the separation control member 2440 moves in the
direction of W51 to the second position shown in part (c) of Figure 192, the
developing unit 9 rotates in the direction of the arrow VI in part (b) of Figure 192,
and the spring-hooked portion 2433c becomes downstream of the straight line
L80 in the VI direction.
[1090] Here, part (a) of Figure 193 to part (c) of Figure 193 show the
engagement state between the hook shape portion 241Oc and the spring-hooked
portion 2433c in part (a) of Figure 192 to part (c) of Figure 192, respectively.
Referring to part (a) of Figure 193 to part (c) of Figure 193, the direction of the
force received from the urging member 2410 to the spring-hooked portion 2433c
in each engaged state will be described.
[1091] First, part (a) of Figure 193 will be explained. In part (a) of Figure
193 and part (a) of Figure 192, the developing unit 9 is in the developing position,
and the spring-hooked portion 2433c is placed on the downstream side in the
arrow V2 direction from the straight line L80.
[1092] As described above, several turns of the coil on one end side of the
urging member 2410 are supported by the urging member seating portion 2481b
and the urging member outer diameter supporting portion 2488c, so that is
supported substantially linearly in the direction substantially normal to the urging
member seating portion 2481b.
[1093] On the other hand, the hook shape portion 2410c of the urging member
2410 is engaged with the spring-hooked portion 2433c placed on the downstream
side in the arrow V2 direction from the straight line L80. Therefore, the urging
member 2410 is arranged between the urging member supporting portion 2481
and the spring-hooked portion 2433c in an inclined state relative to the straight
line L80.
[1094] The hook shape portion 2410c is engaged with the cylindrical spring
hooked portion 2433c. The inner diameter of the hook shape portion 2410c is
larger than the outer diameter of the cylindrical portion of the spring-hooked
portion 2433c, and therefore, the hook shape portion 2410c is rotatable relative to
the spring-hooked portion 2433c.
[1095] Here, the intersection of the line L81 connecting the swing axis K of
the developing unit 9 and the center of the spring-hooked portion 2433c and the
cylindrical shape of the spring-hooked portion 2433c is a position P24b. Next,
the position P24a of the hook shape portion 241Oc and the spring-hooked portion
2433c when the developing unit 9 shown in part (a) of Figure 192 is in the
developing position is located on the downstream side in the arrow VI direction
from the position P24b.
[1096] The urging member 2410 is a compression coil spring compressed
between the urging member supporting portion 2481 and the spring-hooked
portion 2433c. At position P24a, the columnar portion of the spring-hooked
portion 2433c contacts the coil-side (one end side) portion of the hook shape
portion2410c. Asa result, the force received by the cylindrical portion of the
spring-hooked portion 2433c is directed toward the center of the spring-hooked
portion 2433c cylindrical portion. That is, the spring-hooked portion 2433c
receives a force from the urging member 2410 in the direction of the arrow F85
in part (a) of Figure 192 and part (a) of Figure 193.
[1097] The directions of the arrow F85 in part (a) of Figures 192 and 193 (a)
are inclined toward the arrow V2 in part (a) of Figure 192 with respect to the
straight line L80. By doing so, the developing unit 9 which receives the force in
the direction of arrow F85 from the urging member 2410 is urged to rotate in the
direction of V2 (from the retracted position to the developing position). That is,
as shown in part (a) of Figure 192, when the developing unit 9 is placed at the
developing position, the urging member 2410 is at the contact holding position
(second position) in which the developing unit 9 can move to the developing
position.
[Separation operation]
[1098] Subsequently, the process of moving from the state shown in part (a) of
Figure 192 to the state shown in part (c) of Figure 192 by way of the state shown
in part (b) of Figure 192 will be described. Part (b) of Figures 192 and (c) show
the state in which the separation control member 2440 is moving from the first
position to the second position, and the developing unit 9 is moving from the developing position (contact position) to the retracting position (separation position).
[1099] When the separation control member 2440 moves from the first
position shown in part (a) of Figure 192 in the W51 direction in part (a) of Figure
192, the first force application surface 2440b and the retracting force receiving
portion 2433m come into contact with each other, so that the developing unit 9
rotates about the swing axis K in the direction of the arrow VI in part (b) of
Figure 192 (state shown in part (b) of Figure 192). In part (b) of Figure 192, as a
result of the developing unit 9 rotating in the VI direction from part (a) of Figure
192, the spring-hooked portion 2433c is on the straight line L80. As the spring
hooked portion 2433c moves, the hook shape portion 2410c rotates with respect
to the spring-hooked portion 2433c from the state shown in part (a) of Figure 193,
and is brought into contact with the spring-hooked portion 2433c at the position
P24b in part (b) of Figure 193. In this state, the urging member 2410 is placed
in a compressed state between the urging member supporting portion 2481 and
the spring-hooked portion 2433c substantially in parallel with the straight line
L80.
[1100] At position P24b, the spring-hooked portion 2433c receives a force
from the urging member 2410 in the direction of the arrow F86 in part (b) of
Figures 192 and 193 (b), which is substantially the same direction as the straight
line L80. That is, the force in the direction of the arrow F86 is directed toward
the center of the swing axis K of the developing unit 9, and therefore, the moment
for rotating the developing unit 9 is unlikely to be produced.
[1101] Next, with the movement from the position shown in part (b) of Figure
192 to that shown in part (c) of Figure 192, the spring-hooked portion 2433c
moves toward downstream of the straight line L80 in the arrow VI direction.
As described above, since the inner diameter of the hook shape portion 2410c is larger than the outer diameter of the cylindrical portion of the spring-hooked portion 2433c, the hook shape portion 2410c is rotatable with respect to the spring-hooked portion 2433c. Therefore, as the spring-hooked portion 2433c moves, the hook shape portion 2410c rotates relative to the spring-hooked portion
2433c from the state shown in part (b) of Figure 193, and it is brought into
contact with the spring-hooked portion 2433c at the position P24c in part (c) of
Figure 193.
[1102] In this state, the spring-hooked portion 2433c receives a force at the
position P24c in the direction of the arrow F87 in part (c) of Figure 193 toward
the center of a columnar portion of the spring-hooked portion 2433c.
[1103] As shown in the direction of the arrow F87 in part (c) of Figure 193, it
is inclined with respect to the straight line L80 toward the downstream side of the
arrow VI in part (b) of Figure 192, and is placed in a compressed state between
the urging member supporting member 2481 and the spring-hooked portion
2433c. By this, the developing unit 9 which receives the force in the direction
of arrow F87 from the urging member 2410 is urged by a moment in the VI
direction (direction from the developing position to the retracted position).
[1104] In this manner, the spring-hooked portion 2433c moves as the
developing unit 9 rotates, so that the direction of the force acting on the spring
hooked portion 2433c by the urging member 2410 is switched. Bythis,the
urging direction of the urging member 2410 on the spring-hooked portion 2433c
is the same as the direction in which the developing unit moves from the contact
holding position to the separation holding position, and therefore, the urging
member 2410 can be stably moved from the holding position (second position) to
the separation holding position (first position). The developing unit 9 rotates
until the developing frame comes into contact with a rotation stop portion
(positioning portion at the time of retraction) (not shown) provided on the drum frame of the drum unit 8, and is positioned in contact with the rotation stop portion and is maintained at the retracted position (separation position). At this time, it can be said that the developing unit 9 is stably held in the retracted position (separated position) by the drum unit 8.
[1105] Part (d) of Figure 192 shows a state in which the developing unit 9 is in the retracted position and the separation control member 2440 is in the home
position. Similarly, to the Embodiment 9, even when the separation control
member 2440 is at the home position, the developing unit 9 is maintained at the
retracted position, and the separation control member 2440 can be maintained in
the state not contacting the force receiving portion 2433e and the retracting force
receiving portion 2433m. Therefore, the developing unit 9 placed at the
retracted position does not apply a load on the separation control member 2440
(state shown in part (d) of Figure 192).
[Contact operation]
[1106] Next, referring to Figure 194, the operation of moving the developing unit 9 from the retracted position to the developed position will be described.
Part (a) of Figure 194 shows a state in which the developing unit 9 is in the
retracted position and the separation control member 2440 is in the home position.
Part (b) of Figure 194 shows a state in which the separation control member 2440
is moving from the home position to the first position in the W52 direction in part
(b) of Figure 194 and the developing unit 9 is moving from the retracted position
to the developing position. Part (c) of Figure 194 shows a state in which the
developing unit 9 is placed at the developing position and the separation control
member 2440 is placed at the first position.
[1107] When the separation control member 2440 moves from the home
position in the arrow W52 direction in part (a) of Figure 194, the second force
application surface 2440c of the separation control member 2440 and the force receiving portion 2433e of the development cover member 2433 come into contact with each other, and the developing unit 9rotates in the V2 direction in part (b) of Figure 194. As the developing unit 9 rotates in the V2 direction in part (b) of Figure 194, the spring-hooked portion 2433c changes from the state of part (c) of Figure 193 to the state of part (b) of Figure 193 by way of the state of part (a) of Figure 193. In the state of part (a) of Figure 193, the urging member
2410 is in the contact holding position (second position) for applying a moment
in the V2 direction to the developing unit 9.
[1108] When the urging member 2410 moves to the contact holding position,
the developing unit rotates in the V2 direction in part (b) of Figure 194 and
moves to the developing position in which the developing roller 6 and the
photosensitive drum 4 are in contact with each other (state shown in part (c) of
Figure 194). The separation control member 2440 moved to the first position is
separated from the force receiving portion 2433e of the developing unit 9 moved
to the developing position, so that no load is applied to the separation control
member 2440 from the developing unit 9. At this time, it can be said that the
developing unit 9 is stably held at the developing position (contact position) by
the drum unit 8.
[1109] As described above, the acting direction of the urging member 2410 is
switched from the direction of the arrow F85 in part (a) of Figure 194 to the
direction of the arrow F87 in part (c) of Figure 194, and the direction of the
moment for rotating the developing unit 9 by the urging member 2410 switches
from the direction of the arrow VI in part (c) of Figure 194 to the direction of the
arrow V2 in part (b) of Figure 194. That is, since the urging direction of the
urging member 2410 to the developing unit 9 is the same as the rotational
direction of the developing unit 9 by the movement of the separation control
member 2440, the urging member 2410 can be stably moved from the separation holding position (first position) to the contact holding position (second position).
[1110] In this embodiment, the urging member 2410 comprises a compression
coil spring, but the present invention is not limited to such an example. That is,
the urging member 2410 may include a tension spring. However, in order to
align the moving direction of the separation control member 2440 with the urging
direction of the urging member to the developing unit 9, it is necessary that a
movable member 950 for switching the rotational direction as shown in the
Embodiment 13 is additionally provided.
[Holding mechanism]
[1111] In the above-described embodiment, the structure for the drum unit 8 to
stably hold the developing unit 9 at the retracted position and the developed
position is the urging member 2410 capable of taking the first position and the
second position is the holding portion. However, it is also possible to see the
structure of this embodiment as follows. That is, as a holding mechanism with
which the drum unit 8 stably holds the developing unit 9 at the retracted position
and the developing position, at least the urging member 2410, the urging member
supporting portion 2488, and the spring-hooked portion 2433c can be mentioned.
In this case, it can be said that when the urging member takes the first position
and the developing unit 9 takes the retracted position, the holding mechanism is
in the first state, and when the urging member 2410 takes the second position and
the developing unit 9 takes the developing position, the holding mechanism is in
the second state.
[1112] According to the structure of this embodiment described above, the
same effects as those of Embodiment 1 and 9 can be provided.
[1113] Further, according to this embodiment, since the direction in which the
developing unit 9 is urged by the urging member 2410 can be changed to match
the direction in which the developing unit 9 is urged by the separation control member 2440, the movement of the urging member 2410 between the contact holding position (second position) and the separation holding position (first position) can be stabilized. That is, the control of the attitude of the developing unit 9 can be stabilized.
<Embodiment 22>
[1114] Referring to Figures 195 and 196, an embodiment of the process
cartridge and the image forming apparatus according to embodiment 22 of the
present invention will be described.
[1115] In this embodiment, structures and operations different from those of
the Embodiment 9 will be mainly described, and description of similar structures
and operations will be omitted. For the structure corresponding to that in above
described Embodiment 9, the same reference numerals and characters are
assigned, or the reference numerals in the first part is changed while the reference
numerals and characters in the second part are the same.
[1116] In this embodiment, the developing unit 9 maintains the retracted
position by engaging between the tray 110 which supports the process cartridge P
and the holding member 2510 of the image forming apparatus main assembly 502
described in the Embodiment 9. The details will be described below.
[1117] The mounting portion 110a for mounting the process cartridge of the
tray 110 shown in Figures 130 and 134 is provided with a plurality of partitions
1Ob (110bM, 110bC, in Figures 195 and 196) corresponding to the process
cartridges PY, PM, PC, and PK, respectively. By these partitions 110b, four
spaces for accommodating the four process cartridges PY, PM, PC, and PK are
formed the mounting portion 11Oa.
[1118] Figures 195 and 196 are illustrations of the second process cartridge
PM placed in the second inner position inside the image forming apparatus main assembly 502 shown in Figure 130 of an Embodiment 9, as viewed from the drive-side.
[1119] Referring first to Figure 195, an operation in which the developing unit
9 of the process cartridge PM carried between the partitions 110bM and 110bC
moves from the developing position to the retracted position will be described.
[1120] Part (a) of Figure 195 shows a state in which the developing unit 9 is in
the developing position and the separation control member 540 is in the home
position. Part (b) of Figure 195 and part (c) of Figure 195 show a state in which
the separation control member 540 is moving from the home position to the
second position and the developing unit 9 is moving from the developing position
to the retracting position. Part (d) of Figure 195 shows a state in which the
developing unit is in the retracted position and the separation control member 540
is in the home position.
[1121] The holding member 2510 of this embodiment is the same as that of
the Embodiment 9, and as shown in part (a) of Figure 195, the supported hole
(second contact portion, contact portion) 2510a is rotatably supported by the
supporting shaft 2533c of the development cover member 2533, and is urged by a
tension spring 530 (a urging means) in the direction of the arrow B Iin part (a) of
Figure 195. Further, by the first restricted surface 251Oh of the holding member
2510 being brought into contact with the first restriction surface 2533h of the
development cover member 2533, the rotation of the holding member 2510 urged
by the tension spring 530 is restricted. The holding member 2510 is provided
with a projecting portion (holding portion) 2501b projecting from the supported
hole 251Oa in the direction opposite to that of the photosensitive drum 4, and is
provided with a partition contact portion (engaging portion) 251Os at the free end
of the projecting shape. Further, the holding member 2510 is provided with the
force receiving portion (first force receiving portion, contact force receiving portion) 2510e projecting in the direction of arrow Z2 in part (a) of Figure 195, similarly to the Embodiment 9.
[1122] The development cover member 2533 is fixed to the developing unit 9
as in the Embodiment 9, and is provided with a retracting force receiving portion
(second force receiving portion, separating force receiving portion) 2533m
projecting in the direction of arrow Z2 in part (a) of Figure 195.
[1123] The separation control member 540 of this embodiment is provided in
the image forming apparatus main assembly 502 as in the Embodiment 9. As
shown in part (a) of Figure 195, the force receiving portion 2510e, the separation
control member 540, and the retracting force receiving portion 2533m are
arranged in this order in the arrow W51 direction in part (a) of Figure 195.
Similarly to the Embodiment 9, the separation control member 540 can move
between the first position and the second position. Further, the separation
control member 540 is structured to be movable to a home position at which it
does not contact the force receiving portion 2510e and the retracting force
receiving portion 2533m between the first position and the second position.
[Separation operation]
[1124] When the separation control member 540 moves in the direction which
is from the home position shown in part (a) of Figure 195 toward the second
position (arrow W51 direction), the first force application surface 540b and the
retracting force receiving portion 2533m of the development cover member 2533
are brought into contact with each other, and the first force application surface
540b urges the retracting force receiving portion 2533m. As shown in part (b)
of Figure 195, when the retracting force receiving portion 2533m is urged, the
developing unit 9 is rotated in the V Idirection which is the direction from the
developing position to the retracting position around the swing axis K. At this
time, the holding member 2510 supported by the development cover member
2533 also rotates about the swing axis K in the direction of the arrow VI in part
(b) of Figure 195, and the partition contact portion 251Os of the holding member
2510 is brought into contact with the partition 11ObM. Then, the partition
contact portion 251Os receives a reaction force from the partition 11ObM in the
direction of the arrow N8 in part (b) of Figure 195. By this, the holding member
2510 rotates in the direction of the arrow B2 in part (b) of Figure 195 about the
supported hole (second contact portion) 251Oa and the support portion 2533c, and
the partition contact portion 2510s rotates and moves. Therefore, the partition
contact portion 251Os moves in the direction of arrow Z2 in part (b) of Figure 195
beyond the lower end portion 11ObMa of the partition 11ObM.
[1125] When the separation control member 540 moves from the state shown
in part (b) of Figure 195 in the arrow W51 direction in part (b) of Figure 195 and
moves to the second position shown in part (c) of Figure 195, the partition
contact portion 251Os moves in the arrow W51 direction in part (b) of Figure 195
beyond the partition 11ObM. When the partition contact portion 2510s is
separated from the partition 11ObM, the holding member 2510 is rotated by the
tension spring 530 in the direction of the arrow BI in part (c) of Figure 195 about
the supported hole (second contact portion) 251Oa and the support portion 2533c.
Then, the attitude of the holding member 2510 is restricted by the second
restricted surface 251Ot of the holding member 2510 contacting the lower end
portion 1lObMa of the partition 11ObM (state of part (c) of Figure 195). The
position of the holding member 2510 at this time is a position circumventing the
partition 1ObM in order to engage with the partition 1ObM.
[1126] When the separation control member 540 moves in the arrow W52
direction in part (c) of Figure 195 and returns to the home position from the
second position from the state shown in part (c) of Figure 195, the developing
unit 9 is rotated in the direction of arrow V2 in part (c) of Figure 195 by the driving force received by the development coupling member 74. Then, the holding member 2510 supported by the development cover member 2533 also rotates and moves in the direction of the arrow V2 in part (c) of Figure 195, and the partition contact portion 251Os is brought into contact with the contact portion
11ObMb of the partition 11ObM. When the partition contact portion 2510s
contacts the contact portion (contacted portion, engaging portion) 11ObMb of the
partition 11bM, the rotation of the developing unit 9 stops (state shown in part
(d) of Figure 195). At this time, the holding member 2510 is in the restriction
position (separation holding position, first position) in which, one end of the
projecting portion (holding portion) 2501b contacts (engages) the contact portion
(contacted portion, engaging portion) 11ObMb of the partition 11ObM, and at the
other end, the supported hole 2510a contacts the support portion 2533c. Thatis,
the holding member 2510 is engaged with the partition11ObM. Therefore,the
developing unit 9 is maintained (stably held) at the retracted position (separated
position).
[1127] As shown in part (d) of Figure 195, the separation control member 540
placed at the home position is separated from the holding member 2510 and the
development cover member 2533, and therefore, no load is applied thereto from
the developing unit 9.
[1128] As described above, the developing unit 9 can be moved from the
development position (contact position) to the retracted position (separation
operation) by the operation of the separation control member 540 moving from
the home position to the second position and returning to the home position again.
[Contact operation]
[1129] Next, referring to Figure 196, the operation of moving the developing
unit 9 from the retracted position to the developed position will be described.
Part (a) of Figure 196 shows a state in which the developing unit 9 is in the retracted position and the separation control member 540 is in the home position.
Part (b) of Figure 196 and part (c) of Figure 196 show a state in which the
separation control member 540 is moving from the home position in the W52
direction, and the developing unit 9 is moving from the retracted position to the
developing position. Part (d) of Figure 196 shows a state in which the
developing unit 9 is located at the developing position and the separation control
member 540 is located at the home position.
[1130] As shown in part (b) of Figure 196, when the separation control
member 540 moves in the direction which is from the home position toward the
first position (arrow W52 direction), the second force application surface 540c of
the separation control member 540 and the force receiving portion 251Oe of the
holding member 2510 are brought into contact with each other, and the second
force application surface 540c urges the force receiving portion 2510e. The
holding member 2510 thus urged by the force receiving portion 2510e is rotated
about the supported hole (second contact portion) 2510a and the supporting
portion 2533c in the direction of the arrow B2 in part (b) of Figure 196. When
the holding member 2510 rotates, the partition contact portion 251Os rotationally
moves in the direction of the arrow B2 in part (b) of Figure 196, and therefore,
the partition contact portion 251Os is moved beyond the lower end portion
11bMa of the partition 11bM in the arrow Z2 direction in part (b) of Figure
196, so that the contact portion (contacted portion, engaging portion) 1ObMb
and the partition contact portion 251Os are separated from each other, and the
engagement between the holding member 2510 and the partition 11ObM is
broken. The position of the holding member 2510 at this time is a position
which circumvents the partition 11ObM in order to release the engagement with
the partition 11ObM, and is also a position for allowing the developing unit 9 to
move to the developing position (contact position).
[1131] When the partition contact portion 251Os is separated from the partition
11bM, the partition contact portion 251Os comes into contact with the contact
portion 11ObMb of the partition 11ObM, so that the developing unit 9 maintained
in the retracted position is rotated in the arrow V2 direction by the driving force
received by the development coupling member 74 and the urging force of the
developing unit urging spring 134 (see Figure 131, and so on) and is moved to the
developing position (contact position) (state in part (c) of Figure 196).
[1132] When the separation control member 540 shown in part (c) of Figure
196 moves from the first position in the direction of the arrow W51 in part (c) of
Figure 196 toward the home position, the holding member 2510 is rotated by the
tension spring 530 in the BI direction. Then, the attitude of the holding member
2510 is restricted by the first restricted surface 251Oh of the holding member
2510 coming into contact with the first restriction surface 2533h of the
development cover member 2533. (State of part (d) of Figure 196)
[1133] As shown in part (d) of Figure 196, the separation control member 540
placed at the home position is separated from the holding member 2510 and the
development cover member 2533, so that no load is applied thereto from the
developing unit 9.
[1134] As described above, the developing unit 9 can be moved from the
retracted position to the developed position by the operation of the separation
control member 540 moving from the home position to the first position and
returning to the home position again.
[1135] As described above, the holding member 2510 is provided with a
portion (projecting portion 2501b) projecting from the developing unit 9 (or the
developing frame) in the direction crossing the rotation axis M2 of the developing
roller (in this embodiment, the direction perpendicular to each other). Further,
the projecting portion is provided with an engaging portion 2510s. Therefore, the engaging portion 251Os can be engaged with the tray 110 to hold the developing unit 9 at a predetermined position (retracted position (separated position) in this embodiment).
[1136] The direction in which the holding member 2510 projects from the
developing unit 9 (or the developing frame) is not limited to the direction
crossing the rotation axis M2 of the developing roller (the direction perpendicular
to each other in this embodiment).
[1137] Further, in this embodiment, the holding member 2510 is structured to
engage with the partition 1Ob of the tray 110, but the present invention is not
limited to such an example. For example, the holding member 2510 maybe
engaged with another portion of the tray 110 or another portion of the image
forming apparatus main assembly 502 to hold the developing unit 9 at a
predetermined position. Further, in this embodiment, the position of the
developing unit 9 when the holding member 2510 is engaged with the ray 110 or
the like is the retracted position (separation position), but the developing unit 9
may be held at the developing position (contact position). In this case, in place
of the developing unit urging spring 134, a tension spring (separation direction
urging member) 22541 or the like as described in the 20th embodiment may be
used so that the developing unit 9 is urged in the direction from the developing
position to the retracted position.
[1138] According to the structure of this embodiment described above, the
same effects as those of Embodiment 1 and 9 can be provided.
<Embodiment 23>
[1139] Referring to Figures 197 to 200, a process cartridge and an image
forming apparatus according to the embodiment 23 of the present invention will
be described. In this embodiment, structures and operations different from those of the above-described embodiment 22 will be mainly described, and description of similar structures and operations will be omitted. For the structure corresponding to that in above-described Embodiment 22, the same reference numerals and characters are assigned, or the reference numerals in the first part is changed while the reference numerals and characters in the second part are the same.
[1140] In this embodiment, a part of the tray 110 of the image forming apparatus main assembly 502 described in the 22nd embodiment and supporting
the process cartridge P and the slope 2633b2 of the holding member 2633b which
is a portion of the developing unit 2690 are brought into contact with each other, so that the developing unit 2609 is maintained at the retracted position. The
details will be described below.
[1141] As shown in Figure 197, the mounting portion 110a for mounting the process cartridge of the tray 110 includes a plurality of partitions 110b (110bM,
110bC, and so on) corresponding to the process cartridges PY, PM, PC, and PK, respectively. By these partitions 110b, four spaces for accommodating the four
process cartridges PY, PM, PC, and PK are formed in the mounting portion 110a.
[1142] Figures 197 to 200 are illustrations of the second process cartridge PM placed at the second inner position inside the image forming apparatus main
assembly 502 shown in Figure 130 of the Embodiment 9, as viewed from the
drive-side. For better illustration, Figures 197 to 200 are illustrations in which
the tray 110 is partially cut so that the separation control member and the
partition 11Ob can be seen. Figures 201 to 203 are partially enlarged views of
the holding member portion in each embodiment, in which (a) shows a state of a
retracted position, and (b) shows a state of a developed position.
[Movement to development position]
[1143] First, referring to Figures 197 to 198, the operation of the developing unit 2609 of the process cartridge PM installed between the partitions 11ObM and
11bC from the retracted position to the developing position will be described.
Part (a) of Figure 197 shows a state in which the developing unit 2609 is in the
retracted position and the separation control member 26540 is in the home
position. Part (b) of Figure 197 and part (a) of Figure 198 show a state in which
the separation control member 26540 is moving from the home position to the
first position and the developing unit 2609 is moving from the retracted position
to the developing position.
[1144] Part (b) of Figure 198 shows a state in which the developing unit 2609
is in the developing position and the separation control member 26540 is in the
home position.
[1145] The separation control member 26540 of this embodiment is provided
in the image forming apparatus main assembly 502 as in the Embodiment 9. As
shown in part (a) of Figure 197, the force receiving portion 2633e, the separation
control member 26540, and the retracting force receiving portion 2633a are
arranged in this order in the arrow W51 direction. Similarly to an Embodiment
9, the separation control member 26540 can move between the first position and
the second position. Further, the separation control member is structured to be
movable to the home position in which the force receiving portion 2633e and the
retracting force receiving portion 2633a do not contact each other, between the
first position and the second position.
[1146] The development cover member 2633, which is a portion of the
developing frame, is provided with a force receiving portion 2633e and a
retracting force receiving portion 2633a. Further, the development cover
member 2633 is provided integrally with a holding member 2633b. The holding
member 2633b is provided with an elastic portion 2633f which flexes when a
force is applied, a curved surface 2633bl, and a slope 2633b2. Inthis embodiment, elasticity is provided by a molded leaf spring made of resin mold.
However, as another example, the holding member 2633s may have a metal
spring 2633s1 as shown in Figure 202, or the holding member 2633t itself may be
a metal leaf spring as shown in Figure 203.
[Contact operation]
[1147] When the separation control member 26540 moves from the home position shown in part (a) of Figure 197 in the arrow W52 direction, which is the
direction toward the first position, the first force application surface 26540c and
the force receiving portion provided on the development cover member 2633
(first force receiving portion, contact force receiving portion) 2633e are brought
into contact with each other, so that the first force application surface 26540c
urges the force receiving portion 2633e. As shown in part (b) of Figure 197, when the force receiving portion 2633e urges the first force application surface
26540c, the developing unit 2609 is rotated from the retracted position (separated
position) about the swing axis K toward the developing position (direction of arrow V2 in part (b) of Figure 90.
[1148] At this time, the holding member 2633b provided on the development cover member 2633 also rotates about the swing axis K in the direction of the
arrow V2, and the slope 2633b2 of the holding member 2633b abuts against the
partition 110bC due to the component force of the slope, and the elastic portion
2633f flexes (elastically deforms).
[1149] Then, as shown in part (a) of Figure 198 and part (b) of Figure 201, the surface 110bC2 of the partition 110bC and the curved surface 2633b1 come into
contact with each other, and the holding member 2633b is placed in the gap
between the partition 110bC and the developing frame of the developing unit
2609. In this state, the developing unit 2609 is in the developing position
(contact position), and the developing unit is maintained in the developing position by the driving torque of the developing roller from the image forming apparatus main assembly and the urging by the developing unit urging spring (see
Figure 130 and the like).
[1150] The curved surface 2633b1 has an arc shape (see part (b) of Figure
201) in which the center of the arc is the same as the swing axis K at the time
when it is bent, and the reaction force produced when the developing unit 2609 is
in the developing position does not act as a moment to rotate the developing unit
2609 in the VI direction or the V2 direction.
[1151] As shown in part (b) of Figure 198, the separation control member
26540 placed at the home position is separated from the force receiving portion
2633e, and therefore, the no load is applied from the developing unit 9.
[1152] As described above, the developing unit 9 is moved from the retracting
position (separation position) to the developing position (contact position) By the
separation control member 26540 moving from the home position to the first
position and returning to the home position again.
[Separation operation]
[1153] Next, referring to Figures 199 to 200, the operation will be described in
which the developing unit 2609 of the process cartridge PM installed between the
partition 110bM and the partition 110bC moves from the development position
(contact position) to the retracted position (separation position). Part (a) of
Figure 199 shows a state in which the developing unit 2609 is in the developing
position and the separation control member 26540 is in the home position. Part
(b) of Figure 199 and part (a) of Figure 200 show a state in which the separation
control member is moving from the home position to the second position and the
developing unit 9 is moving from the developing position to the retracted position.
Part (b) of Figure 200 shows a state in which the developing unit 9 is in the
retracted position and the separation control member 26540 is in the home position.
[1154] When the separation control member 26540 moves from the home
position shown in part (a) of Figure 199 in the arrow W51 direction, which is the
direction toward the second position, the first force application surface 26540b is
brought into contact with and urges force receiving portion (second force
receiving portion, separating force receiving portion) 2633a provided on the
development cover member 2633.
[1155] As shown in part (b) of Figure 199, when the retracting force receiving
portion 2633a is urged against the first force application surface 26540b, the
developing unit 2609 is rotated about the swing axis K in the direction which is a
direction from the developing position to the retracting position (arrow VI
direction). With further rotation, the elastic deformation of the elastic portion
2633f is restored, and the contact point between the corner portion 11ObC1 of the
partition 11ObC and the holding member 2633b moves from the curved surface
2633b1 to the slope 2633b2 Then, it receives the reaction force F26 from the
corner of the partition 11ObC on the slope 2633b2 (See part (a) of Figure 201).By
the slope 2633b2, a moment for rotating the developing unit 2609 in the arrow
VI direction is produced, and the moment balances with the moment in the V2
direction (gravity of the developing unit 2609, driving torque received from the
apparatus main assembly, and so on), so that the position (separation position) is
maintained (held). That is, in this embodiment, the slope 2633b2 of the holding
member (holding portion) 2633b is an engaging portion which engages with the
corner portion (engaged portion) of the partition 1ObC.
[1156] Then, as shown in part (b) of Figure 200, the separation control
member 26540 located at the home position is separated from the retracting force
receiving portion 2633a, so that no load is applied thereto from the developing
unit 9.
[1157] As described above, by the separation control member 540 moving
from the home position to the second position and returning to the home position
again, the developing unit can be moved from the contact position (contact
position) to the retracted position (separation position), the retracted position can
be maintained.
[1158] In this embodiment, when the developing unit 2609 is in the
developing position, the curved surface 2633b1 and the partition 11ObC are in
contact with each other, but they may be separated from each other. In addition,
the holding member is a projecting portion projecting from the developing unit
(or development frame). And, the projecting direction thereof crosses
(perpendicular to) with the rotation axis M2 of the developing roller in a direction
from the developing unit 2609 toward the drum unit 2608 (or photosensitive
drum). However, the direction in which the holding member 2510 projects from
the developing unit 9 (or development frame) is not limited to such an example,
as will be described with a modification which will be described hereinafter.
[1159] Further, in this embodiment, the holding member 2633b of the
developing unit 2609 is brought into contact with the partition 110bC of the tray
110 to hold the developing unit at a predetermined position (retracted position),
but this is not limiting to the present invention. That is, the holding member
2633b may be contacted with a part of the tray 110 other than the partition bC or
a part of the image forming apparatus main assembly 502 other than the tray 110
to hold the developing unit 2609 at a predetermined position (retracted position).
[1160] Further, in this embodiment, the force receiving portion (contact force
receiving portion) 2633e and the retracting force receiving portion (separation
force receiving portion) 2633a are provided on the development cover member
2633 constituting the developing frame of the developing unit 2609, but the
present invention is not limited to such an example.
[1161] That is, the developing unit is provided with movable members (152R,
152L, and so on) which are pressed by the cartridge pressing unit 191 or the like
and move from the stand-by position to the operating position in the ZA direction
as shown in Embodiments 1 to 8 and the like. Further, a force receiving portion
(contact force receiving portion) 2633e and a retracting force receiving portion
(separation force receiving portion) 2633a are provided at positions where a force
can be received from the separation control member (196) when the movable
member is in the operating position. As a specific example, the retracting force
receiving portion (separation force receiving portion) 2633a is disposed at the
position where the first force receiving portion 152Rk is provided, and the force
receiving portion (contact force receiving portion) 2633e is disposed at the
position where the second force receiving portion 152Rn is provided.
[1162] When the force receiving portion (contact force receiving portion)
2633e receives a force in the W42 direction, the developing unit moves in the
direction which is from the separation position to the contact position, and when
the retracting force receiving portion (contact force receiving portion) 2633a
receives a force in the W41 direction, the force is transmitted from the movable
member to the developing frame so that the developing unit moves in the
direction which is from the contact position to the separation position.
[1163] With such a structure, the above-mentioned contact operation is carried
out, by the developing unit moving in the direction which is a direction from the
separation position to the contact position, and the separation operation described
above is carried out, by the developing unit moving in the direction which is a
direction from the contact position to the separation position.
<Another Example of Embodiment 23>
[1164] Another embodiment, that is, embodiment 23 will be described. In
this embodiment, as shown in Figure 204, the holding member 2633'b is provided so as to project at least in the direction of the rotation axis M2 of the developing roller. The holding member 2633'b is brought into contact with a side surface portion 11ObCS and an almost horizontal surface portion 11ObC3 of the tray 110 to maintain (hold) the developing unit 2609 in the retracted position (separated position).
[1165] A hole (opening, cut-away portion) 520'H is provided in the drive-side cartridge cover member 520', which is a part of the drum frame. The holding
member 2633'b provided integrally with the development cover member 2633'
which is a part of the developing frame penetrates the hole 520'H to contact the
almost horizontal surface portion 110bC3.
[1166] The relationship between the holding member 2633' of the developing unit 2609, the side surface portion 110bCS, and the almost horizontal surface
portion 110bC3 is similar to the relationship between the holding member 2633,
the partition 110bC, the corner portion 110bC1, or the surface 110bC2 in the
above-described embodiment 26.
[1167] Figure 205 is a view illustrating the movement of the holding member 2633' in which the drive-side cartridge cover member 520'is not shown for better
illustration.
[1168] Part (a) of Figure 205 is an illustration showing a state in which the developing unit 2609 is in the retracted position (separated position). At this
time, the slope 2633'b2 and the almost horizontal surface portion 110bC3 are in
contact with the holding member 2633'b, and therefore, the developing unit 2609
is maintained (held) at the retracted position.
[1169] Part (b) of Figure 205 is an illustration showing a state in which the developing unit 2609 is in the developing position (contact position). At this
time, the holding member 2633'b is in a state where at least a portion of the flat
surface 2633'b1 is submerged below the almost horizontal surface portion
110bC3 (see part (c) of Figure 205), and the developing unit 2609 is maintained
(held) in the developing position (contact position).
[1170] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
<Embodiment 24>
[1171] In this embodiment, structures and operations different from those of
the Embodiment 1 described above will be mainly described, and description of
similar structures and operations will be omitted. For the structure
corresponding to that in above-described Embodiment 1, the same reference
numerals and characters are assigned, or the reference numerals in the first part is
changed while the reference numerals and characters in the second part are the
same.
[1172] Figure 206 is a perspective view of the cartridge tray 1771. Figure
207 is a cross-sectional view of a process cartridge 1700C and a cartridge tray
1771, and is a view illustrating the operation related to the separation/contact
mechanism, wherein (a) shows a separation state, and (b) shows a contact state.
[1173] First, the cartridge tray 1771 will be described. As shown in Figure
206, a contacted portion 1771b (M, C, K (Y is unillustrated)) extending inward in
the longitudinal direction is provided at the longitudinal end of the cartridge tray
1771. Since all Y, M, C and K parts have the same structure, the suffix YMCK
will be omitted in the following. The contacted portion 1771 is provided with a
contacted surface 1771c facing the arrow X1 direction (the pushing direction of
the cartridge tray 1771). Further, a second restriction surface 1771d adjacent to
the contacted surface 1771c on the upper side (Z1 direction) is provided.
[1174] Next, referring to Figure 207, the structure of the process cartridge
1700C will be described. The drive-side cartridge cover member 1716C, which is a portion of the drum frame, does not have a portion corresponding to the contacted surface 116c of the process cartridge 100, and instead, a space portion
1716Ce is provided to permit insertion of the contacted portion 1771b of the
cartridge tray 1771. In the other respects, the structure of the process cartridge
1700C is the same as that of the process cartridge 100. Particularly, the process
cartridge 1700C is similar to the process cartridge 100 in that it has a movable
member 1752R and a spacer (restriction member, holding member) 1751R.
[1175] Next, the arrangement when the process cartridge 1700C is mounted
on the cartridge tray will be described. The main difference between the
Embodiment 1 and this embodiment is that the portion corresponding to the
contacted surface 116c of the drive-side cartridge cover member 116 of
Embodiment 1 is the contacted surface 1771c of the cartridge tray 1771.
Therefore, in the spaced state of the developing unit 1709 shown in part (a) of
Figure 207, the contact portion 1751Rc of the spacer 1751R contacts the
contacted surface 1771c. Further, in the contacted state of the developing unit
1709 shown in part (b) of Figure 207, the contact portion 1751Rc of the spacer
1751R is separated from the contacted surface 1771c, and the restricted surface
(restricted portion) 1751Rk contacts the second restriction surface 1771d.
[1176] By applying the above structure, it is possible to provide the contacted
surface on the cartridge tray 1771. The description of the operation of the
separation/contact mechanism is the same as that in the Embodiment 1, and
therefore, the description thereof will be omitted.
[1177] Further, in this embodiment, the contact/separation mechanism is
provided only on the drive-side, but it may be provided only on the non-drive
side or may be provided on both of the drive-side and the non-drive-side. It can
be appropriately selected according to the structure to which the invention is
applied.
[1178] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
<Embodiment 25>
[1179] Referring to Figures 208 to 211, Embodiment 25 of the present
invention will be described. In this embodiment, structures and operations
different from those of the above-described embodiment 14 will be mainly
described, and description of similar structures and operations will be omitted.
For the structure corresponding to that in above-described Embodiment 14, the
same reference numerals and characters are assigned, or the reference numerals in
the first part is changed while the reference numerals and characters in the second
part are the same.
[1180] Figure 208 is an illustration showing a state before the process
cartridge P and the spacer 1110 are engaged. Figure 209 is an illustration
showing a state in which the process cartridge P and the spacer 1110 have been
engaged. Figure 210 is a partially enlarged view sequentially illustrating the
process in which the process cartridge P and the spacer 1110 are being engaged
with each other.
[1181] In this embodiment, there is no space between the force receiving
portion (separation force receiving portion) 111Om and the force receiving
portion (first force receiving portion, contact force receiving portion) 1110e of
the retracting force receiving portion (second force receiving portion) of the
spacer 1110, when the process cartridge P is in a free state (natural state not
mounted to the image forming apparatus 502) and in the state before the tray 110
is lowered.
[1182] As shown in Figure 208, an elastic member 11OSG I(see Figure 210)
and an elastic member 111OSG2 are integrally mounted to the spacer 1110 between the retracting force receiving portion 111m and the force receiving portion 1110e. The elastic members 11OSG Iand 1110SG2 are made of cushioning material such as urethane foam, but elastic members such as low hardness rubber members and silicone members may also be used. Further, the elastic members 11OSG Iand 111OSG2 may be mounted to the retracting force receiving portion 111m and the force receiving portion 11Oe by using double sided tape or an adhesive.
[1183] As shown in part (a) of Figures 208 and 210 (a), a slit portion 110SL is provided between the elastic members 11OSG Iand 1110SG2, and in the free
state of the process cartridge, the elastic members 11OSG Iand the elastic
members 1110SG2 are in close contact with each other without a gap
therebetween. In this example, two elastic members are used, but a structure in
which a slit portion is provided in single elastic member may be used.
[1184] As shown in part (b) of Figure 210, when the process cartridge is lowered in the main assembly, the first force application surface 540b and the second force application surface 540c enter the slit portion 1110SL, and finally,
the state shown in Figure 209 and part (c) of Figure 210 results. Inthisstate,the
retracting force receiving portion 111m and the force receiving portion 1110e
can receive the separation force and the contact force from the separation control
member 540 by way of the elastic members 1110SG1 or 1110SG2 provided
between the force application portions 540b and 540c.
[1185] Figure 211 is an illustration showing an operation in which the developing unit 9 moves between the developing position (contact position) and the retracting position (separation position). Part (a) of Figure 211 shows a state
in which the developing unit 9 is in the developing position and the separation
control member 540 is in the home position. When the developing unit 9 is
moved to the retracted position, the separation control member 540 moves in the direction of W51, so that the state shown in part (b) of Figure 211 is changed to the state shown in part (c) of Figure 211. When the separation control member
540 moves from there in the W52 direction and returns to the home position, the
developing unit 9 is placed in the retracted position as shown in part (d) of Figure
211. When the developing unit 9 is moved to the developing position, the
separation control member 540 moves in the direction of W52 from the state
shown in part (d) of Figure 211 to move the developing unit 9 to the developing
position, and then the separation control member 540 moves in the direction W51
to return to the home position, and the state shown in part (a) of Figure 211
results.
[1186] Such movement between the developing position (contact position) and
the retracting position (separation position) of the developing unit 9 is the same
operation as that in the Embodiment 11 described above, and therefore, the
details thereof will be omitted. In this embodiment, even when the separation
control member 540 is in the home position, the separation control member 540
and the elastic members 11OSG Iand 111OSG2 are in contact with each other.
Therefore, the elastic force of the elastic members 11OSG Iand 111OSG2 is
relatively small so that a high load is not applied to the separation control
member 540.
[1187] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
[1188] Further, according to this embodiment, in the space between the
retracting force receiving portion (second force receiving portion, separation
force receiving portion) 111Om and the force receiving portion (first force
receiving portion, contact force receiving portion) 1110e, the elastic members
11OSG Iand 111OSG2 are provided. By providing the elastic members
11OSG Iand 111OSG2 in this manner, it is possible to prevent foreign matter from entering the space between the two force receiving portions with the result of incapability of receiving the force from the separation control member 540.
<Another example of Embodiment 25>
[1189] Referring to Figures 212 and 213, another Example of Embodiment 25
will be described. In this other example, only the points different from those of
the 25th embodiment will be described. In this example, the space between the
retracting force receiving portion (second force receiving portion, separating
force receiving portion) 281Om and the force receiving portion (first force
receiving portion, contact force receiving portion) 281Oe of the spacer 2810 can
be closed.
[1190] Figures 212 and 213 are partially enlarged views showing behavior in
which the retracting force receiving portion 281Om and the force receiving
portion 2810e engage with the separation control member. Part(a)ofFigure
213 is a partially enlarged view illustrating a state in which the developing unit 9
is in the developing position, and part (b) of Figure 213 is a partially enlarged
view illustrating a state in which the developing unit 9 is in the retracted position.
[1191] The retracting force receiving portion 2810m and the force receiving
portion 281Oe are rotatably supported by the spacer 2810, and both are structured
to be attracted to each other by the spring member 2810SP. Further, the spacer
2810 is provided with a rotation stop portion 281OSTP1 and a 2810STP2 to
restrict the rotations of the force receiving portion 281Oe and the retracting force
receiving portion 2810m, respectively. Slopes 2810ml and 2810el are provided
at the lower ends of the retracting force receiving portion 281Om and the force
receiving portion 2810e.
[1192] In the free state of the process cartridge P (natural state in which the
process cartridge P is not mounted to the image forming apparatus 502) before
the tray 110 is lowered, the retracting force receiving portion 281Om and the force receiving portion 281e are in close contact with each other and no space is formed therebetween, as shown in Figure 212.
[1193] Next, as shown in part (a) of Figure 213, when the process cartridge P
supported by the tray 110 in the image forming apparatus 502 begins to lower,
the first force application surface 540b and the second force application surface
540c comes into contact with slopes 2810 ml and 2810e1, and opens between the
retracting force receiving portion 281Om and the force receiving portion 281Oe
against the urging force of the spring member 2810SP. Further, as the process
cartridge P lowers, the first force application surface 540b and the second force
application surface 540c enter between the retracting force receiving portion
281Om and the force receiving portion 2810e to further open between the
retracting force receiving portion 281Om and the force receiving portion 2810e.
Finally, the state shown in part (b) of Figure 213 results, in which the first force
application surface 540b and the second force application surface of the
separation control member 540 are in the space formed between the retracting
force receiving portion 281Om and the force receiving portion 2810e.
[1194] Part (a) of Figure 214 is a partially enlarged view illustrating the
relationship between the separation control member 540 and the spacer 2810
when the developing unit 9 is in the developing position, and part (b) of Figure
214 is a partially enlarged view for illustrating the separation control member and
the spacer 2810 in the state in which the developing unit 9 in the retracted
position. Both part (a) of Figure 214 and Figure 214 (b) show a state in which
the separation control member 540 is in the home position. When moving the
developing unit 9 from the developing position to the retracting position, the
separation control member 540 moves in the direction of W51 from the state
shown in part (a) of Figure 214, presses the retracting force receiving portion
281Om to rotate it in the counterclockwise direction and bring it into contact with the rotation stop portion 2810STP2. By the separation control member 540 further moving in the direction of W51, the retracting force receiving portion
281Om in contact with the rotation stop portion 2810STP2 is further pressed, and
the spacer 2810 itself is pressed by way of the rotation stop portion 2810STP2 to
rotate it in the counterclockwise direction. By this, the spacer 2810 is moves to
the restriction position (first position), and the developing unit 9 moves to the
retracted position. Further, the separation control member 540 returns to the
home position while maintaining the developing unit 9 in the retracted position,
by moving in the direction of W52, and the state shown in part (b) of Figure 214
results.
[1195] When moving the developing unit 9 from the retracted position to the
developing position, the separation control member 540 moves in the W52
direction from the state shown in part (b) of Figure 214, presses the force
receiving portion 2810e to rotate it in the clockwise direction and bring it into
contact with the rotation stop 2810STP2. Further, by the separation control
member 540 moving in the W52 direction, the force receiving portion 2810e in
contact with the rotation stop portion 2810STP1 is further pressed, and the spacer
2810 itself is pressed by way of the rotation stop portion 2810STP1 to rotate it
clockwisely. By this, the spacer 2810 moves to the permission position (second
position), and the developing unit 9 moves to the developing position. Further,
the separation control member 540 returns to the home position while
maintaining the developing unit 9 at the developing position by moving in the
direction of W51, and the state shown in part (a) of Figure 214result.
[1196] Further, only one of the retracting force receiving portion 2810m and
the force receiving portion 2810 may be structured to be rotatable (movable)
relative to the spacer 2810.
[1197] In this example, in the state shown in part (a) of Figure 214 and Figure
214 (b), between the retracting force receiving portion 2810m and the rotation
stop portion 2810STP2, and between the force receiving portion 2810e and the
rotation stop portion 2810STP1, there is a slight gap. By providing this gap, a
positional error between the separation control member 540 at the home position
and the rotation stop 281OSTP2 and the rotation stop 281OSTP1 of the developing
unit 9 at the development position and the retracted position is permission
position, and it can be avoided that the separation control member 540 is
subjected to a high load.
[1198] According to the structure of the present alternative embodiment
described above, the same effects as those of Embodiments 1 and 9 can be
provided.
[1199] According to this example, the space between the retracting force
receiving portion (second force receiving portion, separation force receiving
portion) 281Om and the force receiving portion (first force receiving portion,
contact force receiving portion) 2810e can be closed. By closing the space in
this manner, it is possible to prevent foreign matter from entering the space
between these two force receiving portions with the result of incapability of
receiving the force from the separation control member 540.
<Embodiment 26>
[1200] Next, referring to Figures 215 to 224, Embodiment 26 will be
described. In this embodiment, structures and operations different from those of
the Embodiment 1 described above will be mainly described, and description of
similar structures and operations will be omitted. For the structure
corresponding to that in above-described Embodiment 1, the same reference
numerals and characters are assigned, or the reference numerals in the first part is
changed while the reference numerals and characters in the second part are the same.
[1201] The process cartridges 100 of Embodiments 1 to 25 have been
described as including a drum unit 108 and a developing unit 109, but the
cartridge of this embodiment (developing cartridge 2311) does not include a
drum unit 108. In this embodiment, the tray 2371 is provided with a
photosensitive drum 2304 and a charging roller 2305, which are rotatably
supported thereon. The developing unit 2309 is structured as a developing
cartridge 2311 which is removable from the tray 2371. The structure of the tray
2371 and the mounting of the developing cartridge 2311 onto the tray 2371 will
be described hereinafter. Similarly to the Embodiment 1, in the developing
cartridge 2311, the side on which the development coupling portion 2332a of the
development drive input gear is provided is the drive-side, and the opposite side
with respect to the axial direction of the rotating axis M2 of the developing roller
2306 (parallel to the Y1 and Y2 directions in Figure 217) is the non-drive-side.
[1202] Similarly to Embodiment 1, is provided with a separation/contact
mechanism 2350R (see Figure 217) is provided on the drive-side of the
developing cartridge 2311, and a separation/contact mechanism 2350L (see
Figure 218) is provided on the non-drive-side. Further, since the
separation/contact mechanism has almost the same function on the drive-side and
the non-drive-side, R is added to the reference sign of each member on the drive
side, and L is added to the reference sign of each member on the non-drive-side
with the same reference signs except for R and L.
[Tray structure of image forming apparatus]
[1203] Referring to Figures 215 to 216, the tray 2371 which supports the
developing cartridge 2311 will be described in detail. Figures 215 and 216 are
perspective views of the tray 2371 in an image forming apparatus (not shown).
The tray 2371 is provided with a drive-side plate 2371a at the end in the arrow
Y2 direction, a non-drive-side plate 2371b at the end in the arrow Y1 direction,
and a drum holding member 2371c between them, they are formed integrally.
[1204] The drive-side side plate 2371a includes a positioning portion 2371Rv
having straight portions 2371Rvl and 2371Rv2, and has a positioning function
for supporting and positioning the arc portion 2316e (see Figure 217) of the
drive-side supporting member 2316 of the developing cartridge 2311 as will be
described hereinafter. Further, the straight portion 2371Rv Iand the straight
portion 2371Rv2 form a substantially V-shape, and the angleOR formed between
them is larger than 0 0 and smaller than 180 °.
[1205] The non-drive-side plate 2371b is provided with a positioning portion
2371Lv comprising straight portions 2371Lvl and 2371Lv2, and has a
positioning function for supporting and positioning the arc portion 2317e (see
Figure 218) of the non-drive-side supporting member of the developing cartridge
2311 which will be described hereinafter. Further, the straight portion 2371Lvl
and the straight portion 2371Lv2 form a substantially V-shape, and the angleOL
formed between them is larger than 0 ° and smaller than 180 °.
[1206] The drum holding member 2371c rotatably supports the photosensitive
drum 2304. The photosensitive drum 2304 is provided with a drum coupling
member 2343 at the end in the Y2 direction of the arrow, and is structured to
receive a driving force and rotate by engaging with a drum drive coupling on the
main assembly side (not shown). Further, the drum holding member 2371c
rotatably supports the charging roller 2305 on the photosensitive drum by way of
a supporting member (not shown), the peripheral surface of the charging roller
2305 is contacted with the photosensitive drum 23041 to make the charging roller
2305 to be rotated by the photosensitive drum 2304.
[1207] Further, the drum holding member 2371c has a contacted surface
(contact portion) is provided with 2371Rd which faces the separated holding surface (contact portion) 2351Rc (see Figure 226) of the spacer 235IR, and which keeps the developing unit 2309 in a separated state, as in the Embodiment
1. Similarly, on the non-drive-side, the drum holding member 2371c has a
contacted surface (contacting portion) 2371Ld facing the separation holding
surface (contacting portion) 2351Lc of the spacer 2351L. Further,thedrum
holding member 2371c has a longitudinal positioning recess 2371e for
determining the positions of the developing cartridge 2311 in the directions of
arrows Y1 and Y2.
[1208] In addition, the drum holding member 2371c has rotation stop
projections 2371Rk and 2371Lk for rotating and positioning the developing
cartridge 2311 as will be described hereinafter. However, in this embodiment,
only at the position where the developing unit accommodating the yellow (Y)
toner is inserted (hereinafter, the insertion position of each color developing unit
is referred to as a station), the rotation stop projections 2371Rk and 2371Lk for
the yellow developing unit is provided not on the drum holding member 2371c
but on the side plate connecting member 2371w. Further, in this embodiment,
the rotation stop projections 2371Rk and 2371Lk are structured to stop the
rotation of the developing cartridge of the adjacent station in the direction of
arrow X1 instead of the developing cartridge of the station. The rotation stopper
projections 2371Rk and 2371Lk may be provided on the drum holding member
2371c which holds the photosensitive drum of the same station so as to restrict
the rotation of the developing unit of the same station. However, with respect to
one developing unit, it is preferable that the positioning portions 2371Rv, 2371Lv
and the rotation stop projections 2371Rk, 2371Lk are disposed at positions as
remote as possible from each other in the same XZ cross-section (cross portion
consisting of the arrow X direction and the Z direction) on the drive-side and the
non-drive-side, respectively.
[Developing cartridge structure]
[1209] Next, referring to Figures 217 and 218, the developing cartridge 2311
to be mounted on the tray 2371 will be described in detail. Figure 217 is an
assembly perspective view of the drive-side of the developing cartridge 2311
including the separation/contact mechanism 2350R. In this embodiment, in
order that the developing roller 2306 placed in the developing unit is capable of
taking the developing position and the retracting position by moving relative to
the photosensitive drum 2304 (see Figures 215 and 216) supported by the tray
2371, there is provided a drive-side supporting member 2316 which rotatably
supports 2309. When the developing cartridge 2311 is mounted on the tray
2371, the drive-side supporting member is fixed to the tray 2371.
[1210] The drive-side supporting member 2316 is provided with a cylindrical
support portion 2316a which fits with the outer diameter portion of the cylindrical
portion 2328b of the development cover member 2328 and supports it rotatably.
Here, the central axis of the cylindrical support portion 2316a of the development
cover member 2328 is the same as the swing axis K described in the Embodiment
1, and is the rotation center of the developing unit and the development drive
input gear 2332. Hereinafter, this central axis is referred to as a swing axis K.
The development cover member 2328 is provided with supporting member
locking portions 2328m and 2328n extending in the arrow Y2 direction on the
radial outer side of the cylindrical portion 2328b.
[1211] The supporting member locking portions 2328m and 2328n have
supporting member locking surfaces 2328ml and 2328nl which extend toward
the cylindrical portion 2328b of the development cover member 2328 at the end
in the Y2 direction of the arrow and engage with the locked surface 2316h of the
drive-side supporting member 2316 to restrict the movement of the drive-side
supporting member 2316 in the arrow Y2 direction. A gap (not shown) is provided between the locked surface 2316h and the supporting member locking surfaces 2328ml and 2328nl so as not to hinder the rotation of the developing unit 2309 integrated with the development cover member 2328. Further, the drive-side supporting member 2316 has an arc portion 2316e centered on a swing axis K which contacts the straight portions 2371Rvl and 2371Rv2 of the positioning portion 2371Rv of the tray 2371. Further, substantially right above the arc portion 2316e in the arrow Z1 direction, there is provided a pressed portion 2316g pressed by the supporting member pressing portion 2391b which will be described hereinafter. However, the arc portion 2316e does not have to be an arc centered on the center of rotation of the developing unit, and the arrangement and shape are not limited to those of this example. In addition, the drive-side supporting member 2316 is provided with a rotation stop projection
2316f which engages with the rotation stop projection 2371Rk of the tray 2371 in
the directions of arrows X1 and X2. The positioning of the drive-side
supporting member 2316 relative to the tray 2371 will be described hereinafter.
[1212] The separation/contact mechanism 2350R includes a spacer 2351R which is a restriction member (separation holding member), a movable member
2352R which is a pressing member, and a tension spring 2353. Similarly to the
Embodiment 1, the development cover member 2328 is provided with a first
supporting portion 2328c and a second supporting portion 2328k. The first
supporting portion 2328c is fitted with the support receiving portion 2351Ra of
the spacer 2351R and is rotatably supported thereby. Further, the second
supporting portion 2328k is fitted with the oblong support receiving portion
2352Ra of the movable member 2352R and is rotatably supported. Further, the
tension spring 2353 urges the movable member 2352R and the spacer 2351R to
attract each other.
[1213] In the foregoing, the structure of the developing unit 2309 on the drive- side is described, and the developing cartridge 2311 on the drive-side after assembly is shown in Figure 219.
[1214] Figure 218 is an assembly perspective view of the non-drive-side of the developing cartridge 2311 including the separation/contact mechanism 2350L.
The developing cartridge includes a non-drive-side supporting member 2317 as a member having the same function as the drive-side supporting member 2316.
[1215] The non-drive-side supporting member 2317 includes a cylindrical support portion (not shown) which fits with the outer diameter portion of the
cylindrical portion 2327a of the non-drive-side bearing 2327 and supports it
rotatably. The non-drive-side bearing 2327 is provided with supporting member
locking portions 2327m and 2327n extending in the direction of arrow Yl. The
supporting member locking portions 2327m and 2327n has, at the end in the
arrow Y1 direction, supporting member locking surfaces 2327ml and 2327nl
which engage with the locked surfaces 2317h and 2317k of the non-drive-side
supporting member 2317 to restrict the movement, in the direction of the arrow Y1, of the non-drive-side supporting member 2317. A gap (not shown) is
provided between the locked surfaces 2317h and 2317k and the supporting
member locking surfaces 2317ml and 2317nl to prevent interference when the
developing unit 2309 integrated with the non-drive-side bearing rotates. Here, the central axis of the cylindrical portion 2327a of the non-drive-side bearing
2327 is the same as the swing axis K described above, and is also the rotation
center of the developing unit 2309. Further, the non-drive-side supporting
member 2317 has an arc portion 2317e centered on a swing axis K which
contacts the straight portions 2371Lvl and 2371Lv2 of the positioning portion
2371Lv of the tray 2371. In addition, substantially right above the arc portion
2317e in the arrow Z1 direction, there is provided a pressed portion 2317g
pressed by the supporting member pressing portion 2390b which will be described hereinafter. However, the arc portion 2317e does not have to be an arc centered on the center of rotation of the developing unit, and the arrangement and shape are not limited to those of this example. In addition, the non-drive side supporting member 2317 is provided with a rotation stop recess 2317f which engages with the rotation stop projection 2371Lk of the tray 2371 in the directions of arrows X1 and X2. The positioning of the non-drive-side supporting member 2317 with respect to the tray will be described hereinafter.
[1216] Similarly to the Embodiment 1, the non-drive-side is provided with a development pressure spring 2334 as an urging member for producing an urging
force for bringing the developing roller into contact with the photosensitive drum
2304. The development pressure spring 2334 is assembled between the spring
hooked portion 2327k of the non-drive-side bearing 2327 and the spring-hooked
portion 2317m of the non-drive-side supporting member 2327. In this
embodiment, the spring-hooked portion 2317m of the non-drive-side supporting
member 2327 is disposed on the downstream side in the arrow BB direction (same as the BB direction described in Example 1) with respect to the spring
hooked portion 2327k of the non-drive-side bearing 2327, and the development
pressure spring 2334 is used as a tension spring, but the development pressure
spring 2334 may be used as a compression spring by disposing the spring-hooked
portion 2317m on the upstream side in the arrow BB direction. Further, an
urging member or the like having the same function as the development pressure
spring 2334 which brings the developing roller 2306 into contact with the
photosensitive drum 2304 may be provided on the tray 2371, and the structure for
applying the urging force is not limited to such examples. The
separation/contact mechanism 2350L includes a spacer 2351L which is a
restriction member, a movable member 2352L which is a pressing member, and a
tension spring 2353. Similarly to the Embodiment 1, the non-drive-side bearing
2327 is provided with a first supporting portion 2327b and a second supporting
portion 2327e. The first supporting portion 2327b is fitted with the support
receiving portion 235ILa of the spacer 235IL and is rotatably supported thereby.
Further, the second supporting portion 2327e is fitted with the oblong support
receiving portion 2352La of the movable member 2352L and is rotatably
supported thereby. Further, the tension spring 2353 urges the movable member
2352L and the spacer 235IL to attract each other.
[1217] Further, the non-drive-side end of the developing frame 2325 is
provided with a longitudinal positioning projection 2325a which is integral with
the developing frame and projects in the direction of arrow X2 (73 in Figures
219).
[1218] The structure of the non-drive-side developing unit 2309 has been
described in the foregoing, and the non-drive-side developing cartridge 2311 after
assembly is shown in Figure 220.
[1219] With the above-described structure, when the developing unit 2309 is
mounted on the tray 2371, the drive-side supporting member 2316 and the non
drive-side supporting member 2317 are fixed to the tray 2371, by which the
developing unit 2309 is rotatable about the swing axis K.
[Positioning of developing cartridge]
[1220] Next, a structure in which the developing cartridge 2311 is mounted on
the tray 2371 and the position of the developing cartridge 2311 is determined will
be described in detail.
[1221] Figures 221 and 222 are a drive-side perspective view and a non-drive
side perspective view illustrating a process of mounting the developing cartridge
2311 on the tray 2371 for four colors (2311Y, 2311M, 2311C, 2311K). First, on
the drive-side, the position in the arrow Z direction is determined by the contact
of the arc portion 2316e of the drive-side supporting member 2316 with the straight portions 2371Rvl and 2371Rv2 of the positioning portion 2371Rv of the tray 2371 (Figure 215, Figure 217). Further, by engaging the rotation stop projection 2371Rk of the rotation stop projection 2371 with the rotation stop recess 2316f of the drive-side supporting member 2316, the rotation in the XZ cross-section including the arrow X and the arrow Z is restricted (see Figures 215 and 217). Similarly, on the non-drive-side, the position in the arrow Z direction is determined by the contact of the arc portion 2317e of the non-drive-side supporting member 2317 with the straight portions 2371Lvl and 2371Lv2 of the positioning portion 2371Lv of the tray described above (see Figures 215 and 218).
Further, by engaging the rotation stop projection 2371Lk of the tray 2371 with
the rotation stop recess 2317f of the non-drive-side supporting member 2317,
rotation in the XZ cross-section including the arrow X and the arrow Z is
restricted (Figure 215, Figure 218). Further, the longitudinal positioning
projection 2325a disposed on the non-drive-side of the developing frame 2325
engages with the longitudinal positioning recess 2371e of the tray 2371, so that
the movement in the arrow Y direction is restricted (72 and 73 in Figure 215).
With the above positioning structure, the developing unit 2309 can be positioned
with respect to the tray 2371 in the developing unit mounting complete attitude
shown in Figures 223 (drive-side perspective view) and Figure 224(non-drive
side perspective view).
[1222] Referring to Figure 225, a structure in which the tray 2371 is mounted
on the main assembly of the image forming apparatus (not shown) and the
attitude of the developing unit 2309 is maintained will be described. Here, for
simplification of the description, the Y station among the four color stations will
be described as a representative example. The structures which will be
described in the in the following are the same for other stations. Figure 225
shows a drive-side (Figure 225 (part (a) of Figure 225) and the non-drive-side
(part (b) of Figure 225) as viewed in their respective directions when the tray
2371 is mounted in the main assembly of the image forming apparatus and the
front door (synonymous with the front door 11 described in the Embodiment 1)
(not shown) is moved to the closed state. In part (a) of Figure 225 and Figure
225 (b), a part of the supporting member pressing portions 2391b and 2390b is
deleted by the partial cross-sectional line CS, and the details will be described
hereinafter.
[1223] Cartridge pressing units 2390 and 2391 include first force application
portions 2391a and 2390a which have a function of pushing down the movable
members 2352R and 2352L of the developing unit 2309 as in the Embodiment 1.
In addition, they also include the supporting member pressing portion 2391b,
2390b which press the drive-side supporting member 2316 and the non-drive-side
supporting member 2317 against the straight portions (2371Rvl and 2371Rv2,
2371Lvl and 2371Lv2) of the positioning portions 2371Rv and 2371Lv of the
tray 2371 by an urging member (not shown). The supporting member pressing
portions 2391b and 2390b contact the pressed portions 2316g and 2317g,
respectively, and press the drive-side supporting member 2316 and the non-drive
side supporting member 2317 in the direction of arrow ZA with a predetermined
urging force. By this, the positions and orientations of the drive-side supporting
member 2316 and the non-drive-side supporting member 2317 in the XZ cross
section can be stably maintained in the image forming apparatus main assembly.
Also in the Y direction of the arrow, the position of the developing cartridge 2311
is determined in the image forming apparatus main assembly by the longitudinal
position restriction portion (not shown).
[1224] Here, with the structure of this embodiment, it is desirable that the
positioning portion 2371Rv and the rotation stop projection 2371Rk of the tray
2371, the cylindrical support portion 2316a of the drive-side supporting member
2316, and the supporting member pressing portion 2391b of the cartridge
pressing unit 2391 are arranged substantially at the same position in the direction
of the arrows Y. Similarly, on the non-drive-side, it is desirable that the
positioning portion 2371Lv and the rotation stop projection 2371Lk of the tray
2371, the cylindrical support portion 2317a of the non-drive-side supporting
member 2317, and the supporting member pressing portion 2390b of the cartridge
pressing unit are arranged substantially at the same position in the direction of the
arrow Y. By arranging in this manner, the drive-side supporting member 2316
and the non-drive-side supporting member 2317 are constrained from tilting in
the image forming apparatus main assembly, so that unnecessary increase in
sliding resistance when the developing unit 2309 is rotated is suppressed.
[Contact/separation operation of developing unit]
[1225] Since the contact/separation operation in this embodiment is the same
as that in the Embodiment 1 as described hereinafter, the separation/contact
mechanism 2350R on the drive-side will be briefly described, and the description
about the non-drive-side will be omitted because it is the same as the drive-side.
Referring to Figures 226 to 229, the description will be made. The tray 2371
and the supporting member pressing portion 2391b are omitted.
[1226] Figure 226 shows a state in which the developing unit 2309 is placed at
a separated position (retracted position). When the separation control member
2396R moves in the W42 direction from this state, the second force application
surface 2396Ra of the separation control member 2396R and the second force
receiving surface 2352Rp of the movable member 2352R come into contact with
each other, and the movable member 2352R swings in the BB direction about the
support portion 2328k (see Figure 217) of the development cover member 2328.
Further, as the movable member 2352R rotates, the spacer 2351R is rotated in the
B2 direction while the second pressing surface 2352Rr of the movable member
2352R is in contact with the second pressed surface 2351Re of the spacer 235IR.
Then, the spacer 2351R is rotated by the movable member 2352R to the
separation release position (permission position, second position) where the
separation holding surface (contact portion) 2351Rc and the contacted surface
(contacted portion) 2371d of the tray 2371 are separated. By this, the
developing unit 2309 can move from the separated position to the contact
position (development position) where the developing roller 2306 and the
photosensitive drum 2304 are in contact with each other (state in Figure 227).
[1227] Thereafter, the separation control member 2396R moves in the
direction of W41 and returns to the home position (state of Figure 228).
[1228] When the image forming operation is completed and the separation
control member 2396R moves in the W41 direction, the first force application
surface 2396Rb and the first force receiving surface 2352Rm are brought into
contact with each other, and by the first pressing surface 2352Rq of the movable
member 2352R contacting the pressed surface 2326c (see Figure 217) of the
second bearing 2326 on the drive-side, the developing unit is rotated from the
contact position in the direction of arrow VI about the swing axis K (state in
Figure 229).
[1229] Thereafter, the separation control member 2396R moves in the W42
direction and returns to the home position, by which the spacer 2351R contacts
the contact surface 2371d of the tray 2371 again, and shifts to the restriction
position (separation holding position, first position). By this, the state is
established in which the separation control member 2396R does not act on the
movable member 2352R (state in Figure 226).
[1230] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be obtained.
[1231] According to this embodiment, the structure of moving the developing unit between the developing position and the retracting position as described in
Embodiments 1 to 25 can be also applied to a developing cartridge not including
a photosensitive drum or the like.
<Another Example 1 of Embodiment 26>
[1232] In embodiment 26, the tray 2371 is provided with a contacted surface (contacted portion) 2371d which contacts the separation holding surface (contact
portion) 2351Rc of the spacer 2351R. In this Example, a contacted surface
(contacted portion) 2316c is provided on the drive-side supporting member 2316
of the developing unit. In this Example, the structure and operation different
from those of the above-described 26 will be mainly described, and the
description of the same structure and operation will be omitted. The same
reference numerals are assigned to the structures corresponding to the above
described Embodiment 26.
[Developing cartridge structure]
[1233] Similarly to the 26th embodiment, when the developing cartridge 2311 is mounted on the tray 2371, the drive-side supporting member 2316 is fixed to
the tray 2371, and the developing unit 2309 swings relative to the drive-side
supporting member 2316 in the VI and V2 directions about the swing axis K.
[1234] As shown in Figure 242, the drive-side supporting member 2316 has a contact surface (contact portion) 2316c which contacts the separation holding
surface (contact portion) 2351Rc of the spacer 2351R. Further, the developing
cartridge 2311 is provided with a development pressure spring (biasing member)
2334 having one end which is connected to the drive-side supporting member
2316 and the other end which is connected to the drive-side bearing 2326. The
development pressure spring 2334 urges the drive-side bearing 2326 so that the
developing unit 2309 rotates relative to the drive-side supporting member 2316 in
the V2 direction. The V2 direction is a direction in which the developing unit
2309 is moved from the retracted position (separation position) to the developing
position (contact position) when the developing cartridge 2311 is mounted on the
tray 2371.
[1235] The non-drive-side of the developing cartridge 2311 has the same
structure as the drive-side.
[Contact/separation operation of developing unit]
[1236] Since the contact separation operation in this embodiment is the same
as in Embodiments 1 and 26, as will be described hereinafter, the
separation/contact mechanism 2350R on the drive-side will be briefly described,
and the description about the non-drive-side will be the same as that the drive
side, and therefore, it is omitted. The description will be made, referring to
Figures 242 to 245. The tray 2371 and the supporting member pressing portion
2391b are omitted.
[1237] Figure 242 shows a state in which the developing unit 2309 is located
at a separated position (retracted position). When the separation control
member 2396R moves in the W42 direction from this state, the second force
application surface 2396Ra of the separation control member 2396R and the
second force receiving surface 2352Rp of the movable member 2352R come into
contact with each other, and the movable member 2352R swings in the BB
direction about the second supporting portion 2328k (see Figure 217)of the
development cover member 2328. As the movable member 2352R further
rotates, the spacer 2351R is rotated in the B2 direction while the second pressing
surface 2352Rr of the movable member 2352R is in contact with the second
pressed surface 2351Re of the spacer 2351R. Then, the spacer 2351R is rotated
by the movable member 2352R to the separation release position (permission
position, second position) where the separation holding surface (contact portion)
2351Rc and the contacted surface 2316c of the drive-side supporting member
2316 are separated. By this, the developing unit 2309 is enabled to move from
the separated position to the contact position (development position) where the
developing roller 2306 and the photosensitive drum 2304 are in contact with each
other (state shown in Figure 243).
[1238] Thereafter, the separation control member 2396R moves in the
direction of W41 and returns to the home position (state shown in Figure 244).
[1239] When the image forming operation is completed and the separation
control member 2396R moves in the W41 direction, the first force application
surface 2396Rb and the first force receiving surface 2352Rm come into contact
with each other, and by the first pressing surface 2352Rq of the movable member
2352R coming into contact with the first pressed surface 2326c (see Figure 217)
of the drive-side bearing 2326, the developing unit 2309 is rotated from the
contact position in the direction of arrow VI about the swing axis K (state shown
in Figure 245).
[1240] Thereafter, the separation control member 2396R moves in the
direction of W42 and returns to the home position, so that the spacer 2351R
comes into contact with the contacted surface 2316c of the drive-side supporting
member 2316 again and shifts to the restriction position (separation holding
position, first position). By this, the state is established in which the separation
control member 2396R does not act on the movable member 2352R (the state
shown in Figure 242).
[Mounting and dismounting of developing cartridge relative to tray]
[1241] In this alternative embodiment, when the developing cartridge 2311 in
the state where the developing unit 2309 is in the retracted position as shown in
Figure 242 is mounted on the tray 2371, the developing unit 2309 is maintained
in the retracted position. This is because the spacer 2351R contacts the
contacted surface 2316c of the drive-side supporting member 2316 to maintain the state of being in the restriction position (separation holding position, first position). For the same reason, also when the developing cartridge 2311 with the developing unit 2309 in the retracted position is removed from the tray 2371 as shown in Figure 242, the developing unit 2309 maintains the retracted position.
[1242] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
[1243] According to this alternative embodiment, the structure of moving the
developing unit between the developing position and the retracting position as
described in Embodiments 1 to 25 can be applied to the developing cartridge not
including a photosensitive drum or the like.
[1244] Further, according to this embodiment, since the retracted position of
the developing unit 2309 can be determined in the developing cartridge 2311, the
position accuracy of the retracted position can be improved as compared with the
Embodiment 26. In addition, the developing cartridge 2311 can be mounted to
or removed from the tray 2371 while maintaining the retracted position of the
developing unit 2309. Therefore, it is possible to prevent the developing roller
2306 and the photosensitive drum 2304 from coming into contact with each other
when the developing cartridge is being mounted to or removed from the tray
2371.
<Another Example 2 of Embodiment 26>
[1245] In the 26th embodiment and the other embodiment 1 of the 26th
embodiment, the drum holding member 2371c which supports the photosensitive
drum 2304 is integrally structured on the tray 2371. In this alternative Example,
the drum holding member which supports the photosensitive drum and the
charging roller is structured as a drum cartridge which can be mounted to and
dismounted from the tray. Referring to Figures 230 to 234, the description will
be made. In this other embodiment, the structure and operation different from those of the above-described will be mainly described, and the description of the same structure and operation will be omitted. Further, the same reference numerals are assigned to the structures corresponding to the above-described
Embodiment 26.
[1246] Figure 230 is a perspective view of the drive-side showing a process of mounting the developing cartridge 2311 and the drum cartridge 2308 on the tray
2372 for four colors. The tray 2372 is provided with a drive-side plate 2372a at
the end in the arrow Y2 direction and a non-drive-side plate 2372b at the end in
the arrow Y1 direction, and is integrally structured by way of a side plate
connecting member 2372w (Y, M, C, K).
[1247] The drive-side plate 2372a is provided with a drum cartridge positioning portion 2372Rx which determines the position and orientation of the
drum cartridge 2308, and a drum cartridge rotation stop projection 2372Rm.
Similarly, it is provided further with a developing cartridge positioning portion
2372Rv which determines the position and orientation of the developing cartridge 2311, and a developing cartridge rotation stop projection 2372Rk.
[1248] The non-drive-side plate 2372b is provided with a drum cartridge positioning portion 2372Lx which determines the position and orientation of the
drum cartridge 2308, and a drum cartridge rotation stop projection 2372Lm.
Similarly, it is provided further with a developing cartridge positioning portion
2372Lv which determines the position and orientation of the developing cartridge
2311, and a developing cartridge rotation stop projection 2372Lk.
[1249] The drum cartridge 2308 includes a drive-side drum supporting member 2318 and a non-drive-side drum supporting member 2319 which
rotatably support the photosensitive drum 2304, and a drum frame portion 2315
which rotatably supports the charging roller 2305, and they are formed integrally.
The drive-side drum supporting member 2318 has an arc portion 2318e centered on a swing axis K which is in contact with the straight portions 2372Rvl and
2372Rv2 of the positioning portion 2372Rv of the tray 2372. Further,
substantially right above the arc portion 2318e in the arrow Z1 direction, there is
provided a pressed portion 2318g pressed by a drum cartridge pressing portion
(not shown) provided on the image forming apparatus main assembly 170. In
addition, the drive-side drum supporting member 2318 is provided with a rotation
stop projection 2317f which engages with the rotation stop projection 2372Rk of
the tray 2372 in the directions of arrows X1 and X2. Further, the drive-side
drum supporting member 2318 is provided with contacted surface (contacted
portion) 2318c in contact with the separation holding surface (contact portion)
2351Rc of the spacer 2351R to hold the developing unit 2309 in the retracted
position (separation position).
[1250] The positioning of the drive-side drum supporting member 2318 with
respect to the tray 2372 is the same as the above-described structure (structure of
the developing cartridge 2311 and the tray 2371), and therefore, the description
thereof will be omitted. Similarly, the non-drive-side drum supporting member
2319 also has an arc portion 2319e centered on a swing axis K which contacts the
straight portions 2372Lvl and 2372Lv2 of the positioning portion 2372Lv of the
tray 2372. Further, substantially right above the arc portion 2319e in the arrow
Z1 direction, there is provided a pressed portion 2319g pressed by a drum
cartridge pressing portion (not shown). In addition, the non-drive-side drum
supporting member 2319 is provided with a rotation stop projection 2317f for
engagement with the rotation stop projection 2372Lk of the tray 2372 in the
directions of arrows X1 and X2. Since the positioning of the non-drive-side
drum supporting member relative to the tray 2372 is the same as the above
described structure, the description thereof will be omitted.
[1251] Next, positioning of the drum cartridge 2308 on the tray 2372 will be described. First, as shown in Figures 231 and 232, the drum cartridge 2308 is pressed toward the positioning portions 2372Rv and 2372Lv of the tray 2372 in the Z2 direction by the main assembly drum cartridge pressing portion (not shown). By this, as shown in Figures 233 and 234, the arc portions 2318e and
2319e are pressed against the straight portions 2372Rvl, 2372Rv2, 2372Lvl and
2372Lv2 in the Z2 direction. By this, the position of the drum cartridge in the
Z2 direction is determined. Further, the drum cartridge rotation stop projections
2372Rm and 2372Lm of the tray 2372 engage with the drum cartridge rotation
stop recesses 2318f and 2319f of the drive-side drum supporting member 2319
and the non-drive-side drum supporting member 2319, by which the rotation of
the drum cartridge rotation in the XZ plane is restricted. Further, the movement
in the arrow Y direction is restricted by the abutment between an unshown
longitudinal direction abutment portion of the non-drive-side drum supporting
member 2319 and an unshown longitudinal direction restricting portion of the
tray 2372. With the above positioning structure, the drum cartridge 2308 can be
positioned relative to the tray 2372 in the drum cartridge mounting complete
attitude shown in Figures 233 and 234.
[1252] Since the mounting of the developing cartridge 2311 on the tray 2372
is the same as the above-described structure (structure of the developing cartridge
2311 and the tray 2371), the description thereof will be omitted.
[1253] The separation/contact mechanism in this embodiment may be
provided on only one side of the developing unit 2309 on the drive-side or the
non-drive-side, as in the Embodiment 2.
[1254] According to the structure of this embodiment described above, the
same effects as those of the first and Embodiment 9s can be provided.
[1255] According to this alternative embodiment, a structure with which the
developing unit is moved between the developing position and the retracted position as described in Embodiments 1 to 25 can be used with the structure in which the drum cartridge and the developing cartridge can be mounted to and dismounted from the image forming apparatus.
<EMBODIMENT 27>
[1256] Embodiment 27 will be described. In this embodiment, structures and operations different from those of Embodiment 1 described above will be
described, and members including similar structures and functions are assigned
the same reference numerals, and description thereof will be omitted.
[1257] In Embodiment 1, the development pressing spring 134 is provided on
the non-drive side of the process cartridge, and the developing unit 109 is urged
toward the drum unit 108 by the driving torque (drive side) of the development
coupling 32 and the urging force (non-drive-side) of the development pressing
spring 134. In contrast, in Embodiment 27, the development pressing spring
134 of Embodiment 1 is omitted, and the pressing unit 2780 is provided on the non-drive side of the process cartridge 2700.
[Overall structure]
[1258] First, the overall structure of a process cartridge 2700 as a cartridge according to Embodiment 27 will be described. Part (a) of Figure 246 is a
perspective view illustrating the process cartridge 2700 as viewed from the drive
side, and part (b) of Figure 246 is a perspective view illustrating the process
cartridge 2700 as viewed from the non-drive side. Figure 247 is an exploded
perspective view of a developing unit 2709 including a separation/contact
mechanism 150L on the non-drive side.
[1259] As shown in part (a) of Figures 246 to Figure 247, the process cartridge
2700 includes a drum unit 108 including a photosensitive drum 104 and a
charging roller 105 (see Figure 252), and a developing unit 2709 including a developing roller 106 (see Figure 3). The photosensitive drum 104, the charging roller 105, the developing roller 106, the drum unit 108, and the developing unit
2709 constitute a photosensitive member, a charging member, a developing
member, a first unit, and a second unit, respectively. The assembly structure of
the drum unit 108 and the developing unit 2709 and the structure of the contact
and separation mechanism 150 (150L, 150R) are the same as those of
Embodiment 1.
[1260] That is, the developing unit 2709 is movable between a developing
position and a separation position relative to the drum unit 108, and the
developing roller 106 can deposit toner to the photosensitive drum 104 at the
developing position in the process cartridge 2700. In a state where the process
cartridge 2700 takes the separation position, at least a portion of the developing
roller 106 is placed spaced from the photosensitive drum 104. The spacers 151L
and 151R as holding portions regulate the relative positions between the drum
unit 108 and the developing unit 2709, and are movable between a separation
holding position as a first position for holding the developing unit 2709 in the
separation position and a separation release position as a second position for
holding the developing unit 2709 in the developing position.
[1261] Further, the structure on the drive side of the developing unit 2709 is
the same as that of Embodiment 1, and therefore, the structure of the non-drive
side of the developing unit 2709 will be mainly described below. A non-drive
side bearing 2727 fixed to a developing container 125 by a fixing screw 145 and
an adhesive not shown, on the non-drive side of the developing unit 2709. The
non-drive-side bearing 2727 as a bearing member rotatably supports the
developing roller 106, and the separation/contact mechanism 150L is assembled
to the non-drive-side bearing 2727 as described in Embodiment 1.
[1262] The process cartridge 2700 is supported at opposite end portions in a longitudinal direction (axial direction of the photosensitive drum 104) by a drive side cartridge cover member 116 and a non-drive-side cartridge cover member
2717, respectively. For example, the outer diameter portion of the cylindrical
portion 127a of the non-drive-side bearing 2727 is fitted into the developing unit
support hole 117a of the non-drive-side cartridge cover member 2717. The photosensitive drum 104 is fitted into the drum support hole 117b of the non
drive-side cartridge cover member 2717. By this arrangement, the developing
unit 2709 is supported by the drum unit 108 so as to be swingable about a swing
axis K passing through the center of the developing unit support hole 117a.
[1263] Part (a) of Figure 248 is a perspective view illustrating a non-drive side
of the process cartridge 2700 in a state in which the moving member 152L is
placed at a standby position, and part (b) of Figure 248 is a perspective view
illustrating a non-drive side of the process cartridge 2700 in a state in which the
moving member 152L is located at a projecting position. Part (a) of Figure 249
is a front view illustrating the non-drive side of the process cartridge 2700 in a state in which the moving member 152L is placed at the standby position, and
part (b) of Figure 249 is a front view illustrating the non-drive side of the process
cartridge 2700 in a state in which the moving member 152L is placed at the
projecting position. Figure 250 is a cross-sectional view illustrating the non
drive side of the process cartridge 2700 in a state in which the moving member
152L is placed at the projecting position.
[1264] As shown in part (a) of Figure 248 to Figure 250, a pressing unit 2780 is mounted to the non-drive-side bearing 2727. The pressing unit 2780 is a unit
for urging the developing unit 2709 toward the drum unit 108 when the process
cartridge 2700 is mounted (supported) on the tray 171. In other words, the
pressing unit 2780 can urge the developing unit 2709 from the separation position
to the developing position (contact position) to cause the developing roller 106 to contact the photosensitive drum 104. In a state in which the process cartridge 2700 is not mounted on the tray 171 and the process cartridge 2700 is in a free state, the pressing unit 2780 does not urge the developing unit 2709 from the separated position to the developing position.
[1265] That is, in Embodiment 27, the process cartridge 2700 is not provided with the development pressing spring 134 which has been provided in
Embodiment 1, but the pressing unit 2780 performs the same function as the
development pressing spring 134 at the time when the process cartridge is
mounted on the tray 171. In Embodiment 1, the development pressing spring
134 shown in Figure 16 and part (a) of Figure 30 is assembled between the
spring-hooked portion 117e of the non-drive-side cartridge cover member 117
and the spring-hooked portion 127k of the non-drive-side bearing 127.
However, since the development pressing spring 134 is not provided in
Embodiment 27, the spring-hooked portion 117e and 127k are not formed in the
non-drive-side cartridge cover member 2717 and the non-drive-side bearing 2727, as shown in Figure 247 to part (b) of Figure 249.
[Pressing Unit]
[1266] Next, the pressing unit 2780 and the peripheral structure thereof will be described. Figure 251 is a perspective view illustrating a pressing unit 2780
assembled to the non-drive-side bearing 2727. As shown in Figures 250 and
251, the pressing unit 2780 as an urging portion includes a pressing member 2781
as a moving member and a pressing spring 2782 as an elastic member. The
pressing member 2781 is movable to a stand-by position (position shown in
Figure 252) as a third position and a push-in position (position shown in Figure
254) as a fourth position. The pressing member 2781 includes a shaft portion
2781a extending in an axial direction M28 along an axis M27, a contact surface
278lb provided at one end of the shaft portion 2781a in the axial direction M28, and a flange portion 2781c provided at the other end of the shaft portion 2781a in the axial direction M28 and extending radially outward of the shaft portion 2781a.
[1267] The contact surface 2781b functioning as a force receiving portion is
structured to contact a partition 110b functioning as a force applying portion for
an urging portion of the tray 171 in a state in which the process cartridge 2700 is
mounted on the tray 171. The non-drive-side bearing 2727 includes a spring
seat 2727a and a locking portion 2727b provided to face the spring seat 2727a
with a gap therebetween in the axial direction M28. The locking portion 2727b
includes a shaft support portion 2727c which supports the shaft portion 2781a of
the pressing member 2781 slidably in the axial direction M28, and an abutment
surface 2727d which is abutted to by the flange portion 2781c.
[1268] A pressing spring 2782, which is a compression spring, is compressed
between the flange portion 2781c of the pressing member 2781 supported by the
shaft support portion 2727c and the spring seat 2727a. The pressing member
2781 is urged in an urging direction M29 parallel to the axial direction M28 by
the pressing spring 2782, and the flange portion 2781c of the pressing member
2781 abuts against the abutment surface 2727d.
[1269] Figure 252 is a cross-sectional view illustrating the non-drive-side
bearing 2727 and the pressing unit 2780. As shown in Figure 252, in a state of
the flange portion 2781c being in abutment to the abutment surface 2727d, the
contact surface 2781b of the pressing member 2781 projects in the urging
direction M29 beyond the outer surface 2727e of the non-drive-side bearing 2727.
That is, in a state where no external force is applied to the pressing member 2781,
the contact surface 2781b of the pressing member 2781 placed at the stand-by
position is outside the non-drive-side bearing 2727.
[Mounting of process cartridge to tray]
[1270] Next, a state in which the process cartridge 2700 is mounted on the tray
171 will be described. Figure 253 is a cross-sectional view illustrating a state in
which the process cartridge 2700 is mounted on the tray 171. Figure254isan
enlarged cross-sectional view illustrating the pressing unit 2780. As shown in
Figure 253, the tray 171 has four mounting portions 110a in which process
cartridges 2700 corresponding to respective colors can be mounted. The
mounting portions 110a are partitioned by partitions 1Ob, respectively. The
partition 110b is provided so as to be inclined with respect to the axial direction
M28 of the pressing member 2781.
[1271] When the process cartridge 2700 is mounted on the mounting portion
110a of the tray 171, the contact surface 2781b of the pressing member 2781
provided in the process cartridge 2700 is pressed by the partition 110b, as shown
in Figures 253 and 254. The partition 110b extends in a direction inclined with
respect to the axial direction M28 of the pressing member 2781, and therefore,
the pressing member 2781 is pressed in the axial direction M28 by the partition
110b against the urging force of the pressing spring 2782 in the process of
mounting the process cartridge 2700 to the mounting portion 110a. Inother
words, the contact surface 278lb of the pressing member 2781 receives a
pressing force F27 as an external force from the partition 110b. Thepressing
force F27 imparted from the partition 1Ob to the contact surface 2781b of the
pressing member 2781 is produced by the self-weight of the process cartridge
2700 even when the process cartridge 2700 is simply mounted on the mounting
portion 11Oa, but a stronger pressing force F27 is produced by pressing the
process cartridge 2700 by the cartridge pressing unit 190.
[1272] By the pressing force F27, the pressing member 2781 retracts toward
the inside of the non-drive-side bearing 2727 along the axial direction M28. By
this, the pressing member 2781 is moved from the stand-by position to the
pressing position. At this time, the flange portion 2781c of the pressing member
2781 is separated from the abutment surface 2727d of the non-drive-side bearing
2727. And, the pressing member 2781 is pressed and moved by the partition
10b, by which the pressing spring 2782 is further compressed in the axial
direction M28.
[1273] Therefore, the pressing force F28 acts on the spring seat 2727a of the
non-drive-side bearing 2727 from the pressing spring 2782. The pressing force
F28 acts as a moment (urging force) which rotates the developing unit 2709 in the
direction of the arrow V2 about the swing axis K of the developing unit 2709.
That is, the developing unit 2709 is urged toward the developing position. In
other words, the pressing unit 2780 can apply an urging force to the developing
unit 2709 to urge the developing unit 2709 toward the developing position while
receiving the pressing force F27 by the contact surface 2781b of the pressing
member 2781.
[Arrangement of Pressure Unit]
[1274] Here, referring to Figure 252, the arrangement of the pressing unit
2780 will be described in detail. Figure 252 illustrates a state in which the
process cartridge 2700 is viewed in the direction of the rotation axis M2 of the
developing roller 106 when the developing unit 2709 is in the separated position.
As shown in Figure 252, a straight line passing through the rotation axis M2 as
the rotation center of the developing roller 106 and the rotation axis M1 as the
rotation center of the photosensitive drum 104 is referred to as a first straight line
L31.
[1275] And, a direction parallel to the first straight line L31 is referred to as an
arrow D31 direction. Furthermore, with respect to the first straight line L31, a
region on the side where the rotation axis M5 as the rotation center of the
charging roller 105 is not provided is referred to as a first region AD31, and a
region on the side where the rotation axis M5 of the charging roller 105 is provided is referred to as a second region AD32.
[1276] At this time, the pressing spring 2782 of the pressing unit 2780 is
located at a position more remote from the photosensitive drum 104 than the
developing roller 106 in the direction of the arrow D31 and is disposed in the first
regionAD31. The pressing member 2781 of the pressing unit 2780 is placed at
a position more remote from the photosensitive drum 104 than the developing
roller 106 in the direction of arrow D31. Furthermore, entirety of the pressing
members 2781 is in the first region AD31.
[1277] In this manner, the pressing unit 2780 is placed at a relatively lower
portion of the process cartridge 2700. Therefore, when the process cartridge
2700 is mounted to the first mounting position of the mounting portion 11Oa of
the tray 171, the pressing member 2781 moves from the standby position to the
pushed-in position immediately before the process cartridge 2700 reaches the first
mounting position. By this, the load produced on the process cartridge 2700 can
be reduced.
[1278] Further, the pressing unit 2780 is placed at a position relatively remote
from the swing axis K, and therefore, even if the pressing force F28 is relatively
small, a moment for rotating the developing unit 2709 in the direction of the
arrow V2 about the swing axis K can be sufficiently assured. Therefore, the
pressing spring 2782 can be reduced in size and cost. As illustrated in Figure
252, a distance DS1 from the swing shaft K to the spring seat 2727a is longer
than a distance DS2 from the swing shaft K to the rotation axis M2 of the
developing roller 106.
[1279] As described above, in this embodiment, by the process cartridge 2700
being mounted on the mounting portion 11Oa of the tray 171, the developing unit
2709 is urged toward the developing position. In this embodiment, the pressing
unit 2780 is provided only on the non-drive side of the process cartridge 2700, but the drive side of the process cartridge 2700 is urged toward the developing position by the driving torque imparted by the image forming apparatus main assembly 170 to the development coupling 32 as described in Embodiment 1.
Therefore, during image forming operation, the developing unit 2709 can be
stably held at the developing position, and therefore, the printing precision can be improved.
[1280] In a state in which the spacers 15iL and 151R are located at the separation holding position and the developing unit 2709 is located at the
separated position, the spacers 151L and 151R are abutted against the drive-side
cartridge cover member 116 and the non-drive-side cartridge cover member 2717
by the pressing force F28 of the pressing unit 2780 and the above-described
drivingtorque. Therefore, the drive-side cartridge cover member 116 and the
non-drive-side cartridge cover member 2717 can position the developing unit
2709 by way of (sandwiching) the spacers 15iL and 151R, and stably hold the
developing unit 2709.
[1281] In addition, in a state in which the process cartridge 2700 is not mounted on the mounting portion 11Oa of the tray 171, no pressing force F28 of
the pressing unit 2780 and no driving torque is produced, and therefore, the
developing unit 2709 is not urged toward the developing position. This can
prolong the life of the process cartridge 2700. In addition, since no urging force
for urging the developing unit 2709 toward the developing position is produced,
the load produced in the process cartridge 2700 can be reduced, and therefore,
deformation of the process cartridge 2700 can be suppressed.
[1282] Even in the state in which the process cartridge 2700 is not mounted on the mounting portion 110a of the tray 171 (the state illustrated in Figure 252), an
urging force slightly acts on the spring seat 2727a of the non-drive-side bearing
2727 by the pressing spring 2782, but this urging force is much smaller than the pressing force F28, and therefore, no influence results on the extension of the service life of the process cartridge 2700.
[1283] Next, referring to Figures 255 to 258, Embodiment 28 will be
described. In this embodiment, the structures and operations different from
those of Embodiment 27 described above will be described, and the members
having the same structures and functions will be assigned the same reference
numerals, and description thereof will be omitted.
[1284] In Embodiment 27, the pressing unit 2780 is provided in the non-drive
side bearing 2727, and by the process cartridge 2700 being mounted on the
mounting portion 110a of the tray 171, the pressing force F28 is imparted on the
developing unit 2709. As is different, in Embodiment 28, a pressure spring
2882 is provided between the moving member 152L and the non-drive-side
bearing 2827 as the bearing member. The moving member 152L and the
pressing spring 2882 as an elastic member constitute an urging portion 2880.
As in Embodiment 1, the moving member 152L is movable to a standby position
(position shown in Figure 256) as a third position and a projecting position
(position shown in Figure 258) as a fourth position. Hereinafter, the structure
and operation of the pressing spring 2882 will be described in detail.
[1285] Figure 255 is a perspective view illustrating the process cartridge 2800
in the state that the moving member 152L is not pushed by the cartridge pressing
unit 190.
[1286] Figure 256 is a cross-sectional view illustrating the process cartridge
2800 in the state that the moving member 152L is not pushed by the cartridge
pressing unit 190. Figure 257 is a perspective view illustrating the process
cartridge 2800 in the state that the moving member 152L is pushed by the
cartridge pressing unit 190. Figure 258 is a cross-sectional view illustrating the
process cartridge 2800 in the state that the moving member 152L is pushed by the cartridge pressing unit 190.
[1287] As shown in Figures 255 and 256, the process cartridge 2800 as a
cartridge according to Embodiment 28 includes a drum unit 108 and a developing
unit 2809 as a second unit. The developing unit 2809 is swingable about a
swing axis K between a developing position (contact position) in which the
developing roller 106 (see Figure 3) is in contact with the photosensitive drum
104 and a separation position in which the developing roller 106 is spaced from
the photosensitive drum 104.
[1288] As described in Embodiment 1, the cartridge pressing unit 190 as an
urging member force applying unit is provided above the non-drive side of the
process cartridge 2800. The cartridge pressing unit 190 is structured so as to
move downward in the direction of the arrow ZA in interrelation with transition
of a front door 11 (see Figures 2 and 4) of the image forming apparatus main
assembly 170 from an open state to a closed state.
[1289] Spring seats 152Lj and 2827j are formed on the moving member 152L
and the non-drive-side bearing 2827, respectively, and a pressing spring 2882
which is a compressed spring is compressed between these spring seats 152Lj and
2827j.
[1290] Figures 255 and 256 show a state in which the process cartridge 2800
is mounted on the mounting portion 1Oa of the tray 171 (see Figure 253), and
the front door 11 is in the open state. Therefore, the cartridge pressing unit 190
has not yet lowered in the direction of an arrow ZA, and a first force applying
portion 190a of the cartridge pressing unit 190 and a pressed surface 152Lf as a
force receiving portion of the moving member 152L are separated from each
other.
[1291] Figures 257 and 258 illustrate a state in which the process cartridge
2800 is mounted on the mounting portion 110a of the tray 171 (see Figure 253), and the front door 11 is in the closed state. When the front door 11 is brought from the open state to the closed state and the cartridge pressing unit 190 is lowered in the direction of the arrow ZA, the first force applying portion 190a of the cartridge pressing unit 190 pushes the pressed surface 152Lf of the moving member 152L. In other words, the pressed surface 152Lf receives a pressing force F29 as an external force from the first force applying portion 190a.
Accordingly, the moving member 152L moves from the standby position to a
projecting position in which a projecting portion 152Lh projects in the direction
of the arrow ZA of the process cartridge 2800.
[1292] Similarly to Embodiment 1, the projecting portion 152Lh includes a
first force receiving portion 152Lk as a separation force receiving portion and a
second force receiving portion 152Ln as a contact force receiving portion (see
Figures 29 and 35). A first force applying surface 196La as a contact force
applying portion of a separation control member 196L (see Figures 35 and 36)
pushes the second force receiving portion 152Ln of the moving member 152L, by which a force for moving the developing unit 2809 from the separation position
to the developing position is applied to the process cartridge 2800. A second
force applying surface 196Lb as a separation force applying portion of the
separation control member 196L pushes the first force receiving portion 152Lk of
the moving member 152L, by which a force for moving the developing unit 2809
from the developing position to the separation position is applied to the process
cartridge 2800. When the moving member 152L is in the projecting position
(the position illustrated in Figure 258), the second force receiving portion 152Ln
and the first force receiving portion 152Lk can receive forces from the first force
applying surface 196La and the second force applying surface 196Lb of the
separation control member 196L, respectively.
[1293] By movement of the moving member 152L to the projecting position, the spring seat 152Lj of the moving member 152L approaches the spring seat
2827j of the non-drive-side bearing 2827, so that the pressing spring 2882 is
further compressed. Therefore, a pressing force F30 acts from the pressing
spring 2882 to the spring seat 2827j of the non-drive-side bearing 2827. The
pressing force F30 acts as a moment (urging force) effective to rotate the
developing unit 2809 in a direction of an arrow V2 about the swing axis K of the
developing unit 2809. That is, the developing unit 2809 is urged toward the
developing position. In other words, the urging portion 2880 can apply an
urging force to the developing unit 2809 to urge the developing unit 2809 toward
the developing position while receiving the pressing force F29 at the pressed
surface 152Lf of the moving member 152L.
[Arrangement of urging Unit]
[1294] Here, referring to Figure 256, the arrangement of the urging portion
2880 will be described in detail. Figure 256 illustrates a state of the process
cartridge 2800 as viewed in the direction of the rotation axis M2 of the
developing roller 106 when the developing unit 2809 is in the separated position.
As shown in Figure 256, a straight line passing through a rotation axis M2 as the
rotation center of the developing roller 106 and a rotation axis M1 as the rotation
center of the photosensitive drum 104 is referred to as a first straight line L31.
[1295] A direction parallel to the first straight line L31 is referred to as an
arrow D31 direction. Furthermore, with respect to the first straight line L31, the
region on the side where a rotation axis M5 as the rotation center of a charging
roller 105 does not exist is a first region AD31, and the region on the side where
the rotation axis M5 of the charging roller 105 exists is a second region AD32.
[1296] At this time, the pressing spring 2882 of the urging portion 2880 is at a
position more remote from the photosensitive drum 104 than the developing
roller 106 in the direction of the arrow D31 and is in the second region AD32.
The entirety of the pressing spring 2882 is provided so as to overlap the non
drive-side bearing 2827. Therefore, the process cartridge 2800 can be
downsized.
[1297] As described above, in this embodiment, the developing unit 2809 is
urged toward the developing position, by the process cartridge 2800 being
mounted on the mounting portion 110a of the tray 171, and the front door 11
being brought from the open state to the closed state. By this, the same effects
as those of Embodiment 27 are provided.
[1298] Further, even if the process cartridge 2800 is mounted on the mounting
portion 110a of the tray 171, the developing unit 2809 is not urged to the
developing position because the pressing force F30 is not produced in the
developing unit 2809 before the front door 11 is closed. Accordingly, the
service life of the process cartridge 2800 can be further prolonged as compared
with Embodiment 27. In addition, the load produced in the process cartridge
2800 is reduced, and deformation of the process cartridge 2800 can be suppressed.
[1299] Further, even if the process cartridge 2800 is mounted on the tray 171,
the process cartridge 2800 does not receive the above-described pressing force
F27 from the partition 11Ob of the tray 171. Therefore, the force required to
mount the process cartridge 2800 to the mounting portion 110a of the tray 171
can be reduced, and the operability can be improved.
[1300] Next, referring to Figures 259 to 262, Embodiment 29 will be
described. In this embodiment, the structures and operations different from
those of Embodiment 28 described above will be described, and members having
the same structure and function will be assigned the same reference numerals and
description thereof will be omitted.
[1301] In Embodiment 28, the pressing spring 2882 is provided between the
moving member 152L and the non-drive-side bearing 2827. In Embodiment 29, the arrangement of the pressure spring is changed. Hereinafter, the structure and operation of the pressing spring 2982 will be described in detail.
[1302] Figure 259 is a perspective view illustrating the process cartridge 2900
in a state that the moving member 152L is not pushed in by the cartridge pressing
unit 190. Figure 260 is a cross-sectional view illustrating the process cartridge
2900 in a state that the moving member 152L is not pushed by the cartridge
pressing unit 190. Figure 261 is a perspective view illustrating the process
cartridge 2900 in a state that the moving member 152L is pushed by the cartridge
pressing unit 190. Figure 262 is a cross-sectional view illustrating the process
cartridge 2900 in a state that the moving member 152L is pushed by the cartridge
pressing unit 190.
[1303] As shown in Figures 259 and 260, the process cartridge 2900 as a
cartridge according to Embodiment 29 includes a drum unit 108 and a developing
unit 2909 as a second unit. The developing unit 2909 is swingable about a
swing axis K between a developing position (contacting position) at which the
developing roller 106 (see Figure 3) is in contact with the photosensitive drum
104 and a separation position at which the developing roller 106 is separated
from the photosensitive drum 104.
[1304] A spring seat 2990 is supported by the non-drive-side bearing 2927 as
a bearing member so as to be movable in the arrow ZA direction, and a spring
seat 2927j is formed so as to face the spring seat 2990 in the arrow ZA direction.
Between the spring seats 2990 and 2927j, a pressing spring 2982, which is a
compressed spring, is compressed. The spring seat 2990 and the pressing spring
2982 as an elastic member constitute an urging portion 2980. The spring seat
2990 is movable to a standby position (position shown in Figure 259) as a third
position and a lowered position (position shown in Figure 261) as a fourth
position.
[1305] Figures 259 and 260 show a state in which the process cartridge 2900
is mounted on the mounting portion 110a of the tray 171 (see Figure 253), and
the front door 11 is in the open state. Therefore, the cartridge pressing unit 190
has not yet lowered in the direction of the arrow ZA, so that the first force
applying portion 190a of the cartridge pressing unit 190 and the pressed surface
152Lf of the moving member 152L are separated from each other. The
cartridge pressing unit 190 is formed with a pressing portion 190h which faces a
pressed surface 2990a as a force receiving portion of the spring seat 2990 in the
direction of the arrow ZA and which is capable of pressing the spring seat 2990.
[1306] Figures 261 and 262 show a state in which the process cartridge 2900
is mounted on the mounting portion 1Oa of the tray 171 (see Figure 253), and
the front door 11 is in the closed state. When the front door 11 is brought from
the open state to the closed state so that the cartridge pressing unit 190 is lowered
in the direction of the arrow ZA, the first force applying portion 190a of the
cartridge pressing unit 190 pushes the pressed surface 152Lf of the moving
member 152L. Then, the moving member 152L moves to a projecting position
in which the projecting portion 152Lh projects in the arrow ZA direction
(downward) of the process cartridge 2900.
[1307] Simultaneously therewith, the pressing portion 190h of the cartridge
pressing unit 190 pushes the pressed surface 2990a of the spring seat 2990 in the
direction of the arrow ZA. In other words, the pressed surface 2990a of the
spring seat 2990 receives the pressing force F31 as an external force from the
pressing portion 190h. By this, the spring seat 2990 is lowered from the standby
position to the lowered position to approach to the spring seat 2927j of the non
drive-side bearing 2927 with the result that the pressing spring 2982 is further
compressed. Therefore, a pressing force F32 is applied to the spring seat 2927j
of the non-drive-side bearing 2927 from the pressing spring 2982. The pressing force F32 acts as a moment (urging force) which rotates the developing unit 2909 in the direction of the arrow V2 about the swing axis K of the developing unit
2909. Thus, the developing unit 2909 is urged toward the developing position.
In other words, the urging portion 2980 can apply the urging force to the
developing unit 2909 to urge the developing unit 2909 toward the developing
position while receiving the pressing force F31 by the pressed surface 2990a of
the spring seat 2990.
[Arrangement of urging portion]
[1308] Here, referring to Figure 260, the arrangement of the urging portion
2980 will be described in detail. Figure 260 illustrates a state in which the
process cartridge 2900 is viewed in the direction of a rotation axis M2 of the
developing roller 106 when the developing unit 2909 is in the separated position.
As shown in Figure 260, a straight line passing through the rotation axis M2 as
the rotation center of the developing roller 106 and a rotation axis M1 as the
rotation center of the photosensitive drum 104 is referred to as a first straight line
L31. In addition, a straight line passing through a rotation axis M5 as the
rotation center of the charging roller 105 and the rotation axis M1 of the
photosensitive drum 104 is referred to as a third straight line L33, and a tangent
line to the surface of the photosensitive drum 104 at an intersection closer to the
rotation axis M5 of the charging roller 105 of intersections of the third straight
line L33 and the outer peripheral surface of the photosensitive drum 104 is
referred to as a second straight line L32.
[1309] And, a direction parallel to the first straight line L31 is referred to as an
arrow D31 direction. Further, with respect to the 1st straight line L31, a region
on the side where the rotation axis M5 of the charging roller 105 exists is referred
to as a first region AD31, and a region on the side where the rotation axis M5 of
the charging roller 105 exists is referred to as a second region AD32. A region on the side where the rotation axis M5 of the charging roller 105 exists with respect to the second straight line L32 is referred to as a third region AD33.
[1310] At this time, the pressing spring 2982 of the urging portion 2980 is
located at a position more remote from the photosensitive drum 104 than the
developing roller 106 in the direction of the arrow D31 and is disposed in the
third region AD33.
[1311] As described above, in this embodiment, by the front door 11 being
brought from the open state to the closed state after the process cartridge 2900 is
mounted on the mounting portion 110a of the tray 171, the developing unit 2909
is urged toward the developing position. Thus, the same effects as those of
Embodiment 28 can be provided.
<Other Modification Examples of Embodiments 27 to 29>
[1312] In Embodiments 27 to 29, the spacers 15iL and 151R are rotatably
supported by the developing unit, but the present invention is not limited to such
anexample. For example, the spacers 151L and 151R maybe rotatably
supported by the drum unit.
[1313] In Embodiment 27, the pressing unit 2780 is provided only on the non
drive side of the developing unit 2709, but it may be provided also on the drive
side of the developing unit 2709. In this case, the urging force of the pressing
unit provided on the drive side may be set to be lower than the urging force of the
pressing unit provided on the non-drive side in consideration of the driving torque
inputted from the image forming apparatus main assembly 170 to the drive side
of the process cartridge 2700. The pressing unit 2780 may be provided at a
position between the drive side and the non-drive side of the developing unit
2709 in the axial direction of the swing shaft K. Similarly, the urging portions
2880 and 2980 of Embodiments 28 and 29 may be provided on the drive side of
the developing unit or at positions between the drive side and the non-drive side of the developing unit.
[1314] The above-described embodiments may be combined as is appropriate.
For example, the pressing unit 2780 of Embodiment 27 may be applied to the
process cartridge of Embodiment 9.
[1315] The arrangements of the pressing unit 2780 of Embodiment 27 and the
urging portions 2880 and 2980 of Embodiments 28 and 29 are not limited to the
arrangement described in each Embodiment, and the arrangement may be
changed as is appropriate.
[1316] The pressing springs 2782, 2882, 2982 are not limited to compression
springs, and other urging means for urging the developing unit toward the
developing position may be applied. For example, other types of springs such
as a disc spring and a leaf spring, and other elastic members such as rubber and
sponge may be used.
[1317] Next, referring to Figures 263 to 280, Embodiment 30 will be
described. In this embodiment, structures and operations different from those of
Embodiment 1 described in the foregoing will be described, and members having
similar structures and functions are assigned the same reference numerals, and
description thereof will be omitted.
[1318] In Embodiment 1, the spacer 151R is pushed by the movable member
152R which rotates in the direction of the arrow BB (see Figures 24 and 25) to
rotate from the separation holding position to the separation release position
against the urging force of the tension spring 153. In addition, the spacer 151R
is rotated from the separation release position to the separation holding position
by the urging force of the tension spring 153 by the movable member 152R,
which rotates in the direction of the arrow BA (see Figure 2797), pressing the
drive-side bearing 125. In this manner, the spacer 151R which holds the
developing unit 109 at the contact position or the separation position is rotated by receiving the pressing force provided by the movable member 152R or is rotated by the urging force of the tension spring 153.
[1319] As is different, in this embodiment, a cam 3065 which holds the
developing unit 3009 at the developing position or the separation position is
rotated by using a driving force for driving the developing roller 106 of the
developing unit 3009. The structure of this embodiment will be described in
detail.
[Overall Structure Arrangement]
[1320] First, the overall structure of a process cartridge 3000 as a cartridge
according to Embodiment 30 will be described. Part (a) of Figure 263 is a side
view illustrating a drive side of the developing unit 3009 placed in the developing
position (contact position). Part (b) of Figure 263 is a side view illustrating a
drive side of the developing unit 3009 placed in the separated position.
[1321] As shown in part (a) of Figures 263 to Figure 265, the process cartridge
3000 according to this embodiment includes a drum unit 108 including a
photosensitive drum 104 and a charging roller 105 (see Figure 269), a developing
unit 3009 including a developing roller 106, a movable member 152R, a link unit
3040, and a cam unit 3060. The photosensitive drum 104, the charging roller
105, the developing roller 106, the drum unit 108, and the developing unit 2709
constitute a photosensitive member, a charging member, a developing member, a
first unit, and a second unit, respectively.
[1322] The cam unit 3060 has a rotatable cam 3065, which has a cam surface
3065a which can contact a contact portion 3028d provided on the development
cover member 3028 of the developing unit 3009. As described in Embodiment
1, the developing unit 3009 is provided so as to be swingable relative to the drum
unit 108 about the swing axis K which is concentric with the rotation center of
the development coupling portion 132a. The developing unit 3009 is urged so that the developing roller 106 approaches the photosensitive drum 104 by the urging force of the development pressing spring 134 (see Figure 34) and the driving torque received by the development coupling portion 132a from the image forming apparatus main assembly 170.
[1323] The developing unit 3009 is movable between the developing position
and the separated position relative to the drum unit 108, and the developing roller
106 of the process cartridge 3000 can deposit the toner onto the photosensitive
drum 104 in the developing position. In a state in which the process cartridge
3000 is placed at the separated position, at least a portion of the developing roller
106 is placed away from the photosensitive drum 104.
[1324] As shown in part (a) of Figure 263, in a state in which the cam surface
3065a of the cam 3065 is out of contact from the contact portion 3028d of the
development cover member 3028, the developing roller 106 is in contact with the
photosensitive drum 104, and the developing unit 3009 is placed at the
development position. Then, as shown in part (b) of Figure 263, by the cam
3065 rotating to such and extension that the contact portion 3028d of the
development cover member 3028 is pressed by the cam surface 3065a, the
developing unit 3009 moves to the separated position. In the state that the
developing unit 3009 is at the separated position, the developing roller 106 is
separated from the photosensitive drum 104.
[1325] Figure 264 is the perspective view illustrating a drive-side cartridge
cover member 3016, the developing cover member 3028, the movable member
152R, and the link unit 3040. Figure 265 is a perspective view illustrating the
development cover member 3028 and the movable member 152R. Figure 266 is
a perspective view illustrating the development cover member 3028. Parts (a)
and (b) of Figure 267 are perspective views illustrating the movable member
152R. Figure 268 is a side view illustrating the development cover member
3028.
[1326] As shown in Figure 264, the process cartridge 3000 is supported so as
to be sandwiched between the drive-side cartridge cover member 3016 and the
non-drive-side cartridge cover member 117 (see Figure 13). Thelinkunit3040
is supported between the drive-side cartridge cover member 3016 and the
movable member 152R, as will be described hereinafter.
[1327] As shown in Figures 265 to 268, the development drive input gear 132
provided with the development coupling portion 132 a (see Figure 263) is
rotatably engaged with the cylindrical portion 128b of the development cover
member 3028. The development drive input gear 132 is in meshing engagement
with a developing roller gear 131 fixed to the drive-side end portion of the
developing roller 106 (see Figure 263), and the developing roller 106 is rotated
by the rotation of the development drive input gear 132.
[1328] The movable member 152R is provided with a link engaging portion
152Ri and a spring hooked portion 152Rj which project parallel to an axial
direction of the swing shaft K outwardly in the longitudinal direction of the
developing unit 3009. The developing cover member 3028 is also provided
with a spring hooked portion 3028g which projects in the axial direction of the
swing shaft K. A tension spring 3053 is stretched between the spring hooked
portion 152Rj of the movable member 152R and the spring hooked portion 3028g
of the developing cover member 3028, and the movable member 152R is urged in
the direction of the arrow BA and the direction opposite to the direction of the
arrow ZI by the urging force of the tension spring 3053.
[Structure of Link Unit]
[1329] Next, a structure of the link unit 3040 will be mainly described.
Figure 269 is a perspective view illustrating the drive-side cartridge cover
member 3016, the link unit 3040, and the cam unit 3060. Part (a) of Figure 270 and part (b) of Figure 270 are perspective views illustrating the drive-side cartridge cover member 3016. Part (a) of Figure 271 is an enlarged perspective view illustrating a broken line portion in part (b) of Figure 270. Part (b) of
Figure 271 is an enlarged perspective view illustrating a stopper 3044 and the
peripheral structure thereof. Part (a) of Figure 272 is a front view illustrating a
link cam 3042. Part (b) of Figure 272 and part (c) of Figure 272 are perspective
views illustrating the stopper 3044.
[1330] As shown in Figure 269, the drive-side cartridge cover member 3016
covers the cam unit 3060, and the cam unit 3060 includes a cam drive gear 3061
that is engaged with the development drive input gear 132 (see Figure 265).
The cam drive gear 3061 is supported on one end side (drive side) of the drive
transmission shaft 3064 so as to be capable of movement relative to the drive
transmission shaft 3064. A link unit and a cam unit similar to those on the drive
side are provided on the other end side (non-drive side) of the drive transmission
shaft 3064, and the cam unit on the non-drive side is driven by the driving force
transmitted from the drive transmission shaft 3064. In this embodiment, the link
unit 3040 and the cam unit 3060 are provided on each of the drive side and the
non-drive side of the process cartridge 3000, but the link unit 3040 and the cam
unit 3060 may be provided on only one of the drive side and the non-drive side.
[1331] As shown in Figures 264 and 269, the link unit 3040 includes a stopper
link 3041, a link cam 3042, a link spring 3043, and a stopper 3044. Thestopper
link 3041 is provided with an oblong hole 3041a, a round hole 3041b, and a boss
portion 3041c projecting in the axial direction of the swing shaft K. Ashaft
portion 3016d provided on the drive-side cartridge cover member 3016 passes
through the round hole 3041b, and the stopper link 3041 is supported so as to be
rotatable around the shaft portion 3016d.
[1332] A link engaging portion 152Ri formed on the movable member 152R is loosely fitted into the oblong hole 3041a of the stopper link 3041. Whenthe movable member 152R swings in the direction of arrow BA or in the direction of arrow BB about a second support portion 127e (see Figure 265), the link engaging portion 152Ri presses the inner peripheral surface of the oblong hole
3041a, so that the stopper link 3041 rotates around the shaft portion 3016d.
[1333] As shown in Figure 264, Figure 269 to part (b) of Figure 270, and part
(a) of Figure 272, the drive-side cartridge cover member 3016 is provided with a
shaft portion 3016e projecting in a direction away from the shaft portion 3016d.
The link cam 3042 is formed with a round hole 3042a and an oblong hole 3042b
extending in a radial direction perpendicular to the axial direction of the round
hole 3042a. The round hole 3042a is loosely fitted around the large diameter
portion 3016f of the shaft portion 3016e, and the link cam 3042 is supported
rotatably about the large diameter portion 3016f. The boss portion 3041c of the
stopper link 3041 penetrates the oblong hole 3042b. Since the boss portion
3041c of the stopper link 3041 and the oblong hole 3042b of the link cam 3042
are coupled in this manner, the link cam 3042 rotates about the large diameter
portion 3016f in interrelation with the stopper link 3041 rotating about the shaft
portion 3016d.
[1334] Further, as shown in part (a) of Figure 272, the link cam 3042 has a
substantially arc-shaped contact surface 3042c, slip preventing portions 3042d
and 3042e provided at opposite end portions of the contact surface 3042c and
projecting in a direction away from the round hole 3042a beyond the contact
surface 3042c, and a first clearance surface 3042f and a second clearance surface
3042g. The first clearance 3042f surface and the second clearance 3042g
surface are each formed in a substantially arc shape, and are disposed in the
position closer to the round hole 3042a in the radial direction than the contact
surface 3042c. The first clearance surface 3042f is provided on the opposite side of the contact surface 3042c with the slip preventing portion 3042d interposed in the rotational direction of the link cam 3042. The second clearance surface 3042g is provided on the opposite side of the contact surface
3042c with the slip preventing portion 3042e interposed in the rotational direction
of the link cam 3042.
[1335] As shown in part (a) of Figure 270 to part (b) of Figure 271, the drive
side cartridge cover member 3016 is provided with a stopper support portion
3016h which slidably supports the stopper 3044. The stopper support portion
3016h is provided with a first support portion 3016hl and a second support
portion 3016h2, and the first support portion 3016hl and the second support
portion 3016h2 provided a support hole 3016i which extends in a movement
direction D30 which is substantially parallel to the line connecting the rotation
center of the cam unit 3060 and the rotation center of the link cam 3042. The
support hole 3016i penetrates in the axial direction of the swing shaft K (see
Figure 264). In addition, the drive-side cartridge cover member 3016 is formed
with a receiving portion 3016j which extends continuously with the first support
portion 3016hl toward the cam unit 3060 side.
[1336] As shown in part (b) of Figure 272 and part (c) of Figure 272, stopper
3044 is provided with a first supported portion 3044a, a second supported portion
3044b, an abutment portion 3044c, a cam locking portion 3044d, a spring hooked
portion 3044e, and main body portion 3044f. The main body portion 3044f is
structured to penetrate through the support hole 3016i, and the first supported
portion 3044a projects from the body portion 3044f so as to sandwich the second
support portion 3016h2 of the drive-side cartridge cover member 3016. The
second supported portion 3044b projects from the main body portion 3044f so as
to sandwich that the first support portion 3016hl. In this manner, the second
support portion 3016h2 and the first support portion 3016hl are inserted into between the first supported portions 3044a of the stopper 3044 and into between the second supported portions 3044b of the stopper 3044, respectively, by which the stopper 3044 is slidably movable in the movement direction D30.
[1337] The abutment portion 3044c projects from the main body portion 3044f
toward one side in the movement direction D30, and the cam locking portion
3044d projects from the main body portion 3044f toward the other side in the
movement direction D30. The abutment portion 3044c is provided to be
slidable relative to the contact surface 3042c of the link cam 3042, the slip
preventing portions 3042d and 3042e, the first clearance surface 3042f, and the
second clearance surface 3042g.
[1338] The cam locking portion 3044d includes a cam contact surface 3044g
which can contact the cam 3065 of the cam unit 3060, and a force receiving
surface 3044h which is provided on the opposite side of the cam contact surface
3044g. The force receiving surface 3044h is structured to be capable of
contacting the receiving portion 3016j of the drive-side cartridge cover member
3016. The cam contact surface 3044g and the force receiving surface 3044h are
surfaces extending in a direction parallel to the movement direction D30 and the
axial direction of the swing shaft K, respectively.
[1339] As shown in Figure 264 and part (b) of Figure 272 and part (c) of
Figure 272, a link spring 3043 which is a tension spring is stretched between the
spring hooked portion 3044e of the stopper 3044 and the small diameter portion
3016g of the shaft portion 3016e. The stopper 3044 is urged in a direction of
approaching the link cam 3042 by the urging force of the link spring 3043, so that
the abutment portion 3044c of the stopper 3044 moves following the contact
surface 3042c, the slip preventing portions 3042d, 3042e, the first clearance
surface 3042f, and the second clearance surface 3042g of the link cam 3042.
[Structure of Cam Unit]
[1340] Next, the structure of the cam unit 3060 will be described. Figures
273 and 274 are exploded perspective views illustrating the cam unit 3060.
Figure 275 is a sectional view illustrating the cam unit 3060. Figure 276 is a
perspective view illustrating the cam unit 3060.
[1341] As shown in Figures 273 to 276, the cam unit 3060 includes the cam
drive gear 3061, a clutch portion 3062, a coil spring 3063, a cam 3065, and a lid
portion 3066. The cam drive gear 3061 includes a support hole 3061a into
which the drive transmission shaft 3064 is fitted, and recesses 3061b and 3061c
which are provided continuously with the support hole 3061a and which extend
in the radial direction with 180 degrees of phase different from each other.
[1342] The clutch portion 3062 includes a through hole 3062a penetrated by
the drive transmission shaft 3064, engaging portions 3062b and 3062c which can
be engaged with the recesses 3061b and 3061c, respectively, a cylindrical portion
3062d extending in the axial direction, and a cam engaging portion 3062e with
which the cam 3065 engages. The coil spring 3063 includes a coil portion
3063a fitted by tightening the cylindrical portion 3062d of the clutch portion
3062, one end portion 3063b provided at one end in the axial direction of the coil
portion 3063a, and the other end portion 3063c provided at the other end in the
axial direction of the coil portion 3063a.
[1343] The cam 3065 as a holding portion is structured to regulate the relative
position between the drum unit 108 and the developing unit 3009 so as to be
rotatable between a second rotational position (position shown in part (b) of
Figure 263) as a first position for holding the developing unit 3009 at a separation
position by the drum unit 108 and a first rotational position (position shown in
part (a) of Figure 263) as a second position for holding the developing unit 3009
at the developing position by the drum unit 108. The cam 3065 includes a
cylindrical portion 3065b extending in the axial direction, a cam portion 3065c projecting outward in the radial direction from the outer peripheral surface of the cylindrical portion 3065b, and stopper contact portions 3065d and 3065e which extend outward in the radial direction from an outer peripheral surface of the cylindrical portion 3065b at respective positions with phases different from each other by 180 degrees. The cam surface 3065a which can press the contact portion 3028d (see part (b) of Figure 263) of the developing cover member 3028 is formed on the cam portion 3065c. A groove-shaped spring hooked portion
3065f to which one end portion 3063b of the coil spring 3063 is locked is formed
in the cylindrical portion 3065b.
[1344] The lid portion 3066 includes a small diameter portion 3066b, a
medium diameter portion 3066c having an outer diameter larger than that of the
small diameter portion 3066b, and a large diameter portion 3066d having an outer
diameter larger than that of the medium diameter portion 3066c. The small
diameter portion 3066b, the medium diameter portion 3066c, and the large
diameter portion 3066d are provided coaxially and integrally, and have a through
hole 3066a which is penetrated by the drive transmission shaft 3064. The
middle diameter portion 3066c is provided with a groove-shaped spring hooked
portion 3066e with which the other end portion 3063c of the coil spring 3063 is
locked. The large diameter portion 3066d is provided with a groove-shaped pin
engaging portion 3066f provided in the drive transmission shaft 3064 and
engaged with a parallel pin 3067 which rotates integrally with the drive
transmission shaft 3064. The parallel pin 3067 and the pin engaging portion
3066f are engaged with each other, so that the cam unit 3060 is prevented from
disengaging out of the drive transmission shaft 3064.
[Operation of Cam Unit]
[1345] Next, referring to part (a) of Figures 277 to part (b) of Figure 280, the
operation of the cam unit 3060 will be described. Part (a) of Figure 277 is a cross-sectional view illustrating the link unit 3040 and the cam unit 3060 when the developing unit 3009 is placed at the developing position. Part (b) of Figure
277 is a cross-sectional view illustrating an engaged state between the stopper
3044 and the cam 3065. Part (a) of Figure 278 is a cross-sectional view
illustrating the link unit 3040 and the cam unit 3060 immediately before the
developing unit 3009 starts to move from the developing position to the
separation position. Part (b) of Figure 278 is a cross-sectional view illustrating
the separated state of the stopper 3044 and the cam 3065. Part (a) of Figure 279
is a cross-sectional view illustrating the link unit 3040 and the cam unit 3060
when the developing unit 3009 is placed at the separation position. Part (b) of
Figure 279 is a cross-sectional view illustrating an engaged state between the
stopper 3044 and the cam 3065. Part (a) of Figure 280 is a cross-sectional view
illustrating the link unit 3040 and the cam unit 3060 immediately before the
developing unit 3009 starts to move from the separation position to the
developing position. Part (b) of Figure 280 is a cross-sectional view illustrating
the separated state of the stopper 3044 and the cam 3065.
[1346] As shown in part (a) of Figure 263 and part (a) of Figure 277 and part
(b) of Figure 277, in the state where the developing unit 3009 is placed at the
developing position, the cam 3065 is at the first rotation position where the cam
portion 3065c is placed on the opposite side of the contact portion 3028d of the
developing cover member 3028. In the state in which the cam 3065 is placed at
the first rotation position, the cam surface 3065a is separated from the contact
portion 3028d of the developing cover member 3028. At this time, the abutment
portion 3044c of the stopper 3044 is pressed by the contact surface 3042c of the
link cam 3042, and the stopper 3044 is pushed toward the cam 3065 against the
urging force of the link spring 3043. The abutment portion 3044c stably abuts
on the contact surface 3042c by the slip preventing portions 3042d and 3042e provided at both end portions of the contact surface 3042c, even if vibration or the like happens.
[1347] The stopper contact portion 3065e of the cam 3065 is engaged with the stopper 3044. More specifically, the stopper contact portion 3065e of the cam
3065 has an abutment surface 3065g, and the abutment surface 3065g is in contact with the cam contact surface 3044g of the stopper 3044 as a positioning
portion. Thus, the cam 3065 is positioned at the first rotational position.
[1348] In the state that the developing unit 3009 is located at the developing position, the driving force is inputted from the image forming apparatus main
assembly 170 to the development coupling portion 132a of the development drive
input gear 132 during printing operation. More specifically, the development
coupling portion 132a (see part (a) of Figure 263) as the driving force receiving
portion is rotatable in the direction of the arrow V2 as a predetermined direction,
by receiving a driving force for rotationally driving the developing roller 106.
By this, the development drive input gear 132 rotates, and the cam drive gear 3061 which is meshing engagement with the development drive input gear 132
rotates. As shown in Figure 273, parts (a) and (b) of Figure 276, the cam drive
gear 3061 is engaged with the engagement portions 3062b and 3062c of the
clutch portion 3062, and therefore, the clutch portion 3062 rotates in the direction
of the arrow RI integrally with the cam drive gear 3061.
[1349] Since the cam 3065 is engaged with the stopper 3044, rotation in the direction of the arrow RI is restricted. At this time, the coil portion 3063a of
the coil spring 3063 tightening the cylindrical portion 3062d of the clutch portion
and the small diameter portion 3066b of the lid portion 3066, so that the lid
portion 3066 is slightly rotated relative to the cam 3065 in the direction of the
arrowRIO. Then, the coil spring 3063 in which the one end portion 3063b is
locked to the spring-hooked portion 3065f of the cam 3065 and the other end portion 3063c is locked to the spring hooked portion 3066e of the lid portion
3066 rotates by a predetermined amount in a direction of loosening the coil
portion 3063a. Therefore, the driving force is no longer transmitted from the
clutch portion 3062 to the cam 3065, the coil spring 3063, and the lid portion
3066, with the result that the cam 3065, the coil spring 3063, and the lid portion
3066 stop, that is, no longer rotate. As shown in Figure 275, a gap SP 30 is
provided between the coil portion 3063a and the inner diameter surface of the
cylindrical portion 3065b of the cam 3065, so that the coil portion 3063a can be
loosened by a predetermined amount and expanded radially outward.
[1350] As described above, by the coil portion 3063a being loosened, the
tightening force of the clutch portion 3062 to the cylindrical portion 3062d by the
coil portion 3063a is weakened, so that the frictional force between the coil
portion 3063a and the cylindrical portion 3062d and the small diameter portion
3066b is reduced. By this, the driving force is no longer transmitted from the
clutch portion 3062 to the cam 3065, the coil spring 3063, and the lid portion
3066, and the cam driving gear 3061 and the clutch portion 3062 rotate idly in the
direction of the arrow RI with respect to the coil spring 3063. Thecam3065,
the coil spring 3063, and the lid portion 3066 stop and does not rotate. That is,
the clutch portion 3062, the coil spring 3063, and the lid portion 3066 constitute a
clutch 3090 (see Figure 274) capable of interrupting the driving from the
development coupling portion 132a to the cam 3065 when the cam 3065 is
positioned at the first rotational position or the second rotational position by the
stopper 3044.
[1351] When the development drive input gear 132 starts to rotate, the cam
contact surface 3044g of the stopper 3044 receives a rotational force at the
abutment surface 3065g, but the force receiving surface 3044h formed on the side
of the stopper 3044 opposite from the cam contact surface 3044g is in contact with the receiving portion 3016j. The receiving portion 3016j extends in a direction substantially perpendicular to the arrow RI direction, which is the rotational direction of the cam 3065, and is placed downstream of the cam contact surface 3044g and the force receiving surface 3044h of the stopper 3044 in the arrow RI direction. Accordingly, the rotational force received by the stopper
3044 from the cam 3065 is transmitted to the receiving portion 3016j of the drive
side cartridge cover member 3016 by way of the stopper 3044, and therefore, it is
possible to suppress the positional displacement and deformation of the stopper
3044, thus improving an operation stability of the cam 3065.
[1352] When the developing unit 3009 is to be swung from the developing
position to the separated position (as shown in part (a) of Figure 278 and part (b)
of Figure 278), the separation control member 196R (see Figure 25) moves from
the home position in the direction of the arrow W41, and the movable member
152R is rotated in the direction of the arrow BA by being pressed by the
separation control member 196R. Then, in interrelation with the rotation of the
movable member 152R, the stopper link 3041 and the link cam 3042 rotate, and
at the same time, the stopper 3044 moves in a direction away from the cam 3065
by the urging force of the link spring 3043. At this time, the abutment portion
3044c of the stopper 3044 slides on the contact surface 3042c and the slip
preventing portion 3042d of the link cam 3042 to abut on the first clearance
surface 3042f.
[1353] When the stopper 3044 moves in a direction away from the cam 3065,
the stopper 3044 and the cam 3065 is disengaged from each other, and the
rotation restriction of the cam 3065 in the direction of the arrow RI is lifted.
When the rotation restriction of the cam 3065 is ceased, the coil portion 3063a of
the coil spring 3063 is tightened (reduced in diameter), so that the tightening
force of the coil portion 3063a to the cylindrical portion 3062d of the clutch portion 3062 and the small diameter portion 3066b of the lid portion 3066 is recovered. Therefore, the frictional force between the coil portion 3063a and the cylindrical portion 3062d and the frictional force between the coil portion
3063a and the small diameter portion 3066b increase, so that the clutch portion
3062, the coil spring 3063, and the lid portion 3066 rotate integrally. The cam
3065 also rotates integrally with the clutch portion 3062 and the lid portion 3066
by way of the coil spring 3063. For this reason, the entire cam unit 3060 is
integrally rotated in the direction of the arrow RI by the driving force of the
development drive input gear 132.
[1354] The separation control member 196R (see Figure 25) temporarily
moves from the home position in the arrow W41 direction, and then immediately
moves in the direction of the arrow 42 to return to the home position. Then, as
shown in part (a) of Figure 279 and part (b) of Figure 279, the movable member
152R is pressed by the separation control member 196R to rotate in the direction
of the arrow BB. Then, in interrelation with the rotation of the movable member 152R, the stopper link 3041 and the link cam 3042 rotate, and at the same time,
the stopper 3044 moves in a direction of approaching the cam 3065 against the
urging force of the link spring 3043. This is because the abutment portion
3044c of the stopper 3044 slides on the first clearance surface 3042f and the slip
preventing portion 3042d of the link cam 3042 and abuts to the contact surface
3042c.
[1355] The cam 3065 rotated in the direction of arrow RI by the driving force of the development drive input gear 132 rotates 180 degrees from the first
rotational position shown in part (a) of Figure 277 - part (b) of Figure 278 to
reach the second rotational position, and abuts to the stopper 3044. More
specifically, the stopper contact portion 3065d of the cam 3065 has an abutment
surface 3065h, and the abutment surface 3065h is in abutment with the cam contact surface 3044g of the stopper 3044. Thus, the cam 3065 is positioned at the second rotational position.
[1356] As shown in part (b) of Figure 263 and part (a) of Figure 279 and part
(b) of Figure 279, the cam surface 3065a is in contact with the contact portion
3028d of the developing cover member 3028 when the cam 3065 is located at the
second rotational position. When the cam 3065 rotates from the first rotational
position to the second rotational position, the contact portion 3028d is pressed by
the cam surface 3065a. By this, the developing unit 3009 swings from the
developing position to the separated position against the urging force of the
development pressing spring 134 (see Figure 34) and the driving torque received
by the development coupling portion 132a from the image forming apparatus
main assembly 170. The operation of the cam unit 3060 in a state that the
abutment surface 3065h abuts against the cam contact surface 3044g is similar to
that having been described referring to part (a) of Figure 277 and part (b) of
Figure 277, and therefore, the description thereof will be omitted.
[1357] When the developing unit 3009 is to be swung from the separation
position to the developing position, as shown in part (a) of Figure 280 and part
(b) of Figure 280, the separation control member 196R (see Figure 25) moves
from the home position in the arrow W42 direction, and is pressed by the
separation control member 196R, so that the movable member 152R rotates in the
direction of the arrow BB. Then, in interrelation with the rotation of the
movable member 152R, the stopper link 3041 and the link cam 3042 rotate, and
at the same time, the stopper 3044 moves in a direction away from the cam 3065
by the urging force of the link spring 3043. At this time, the abutment portion
3044c of the stopper 3044 slides on the contact surface 3042c and the slip
preventing portion 3042e of the link cam 3042, and abuts to the second flank
surface 3042g.
[1358] By movement of the stopper 3044 in a direction away from the cam
3065, the engagement state between the stopper 3044 and the cam 3065 is broken,
and the rotation restriction of the cam 3065 in the direction of the arrow RI is
stopped. The operation of the cam unit 3060 when the engagement state
between the stopper 3044 and the cam 3065 is broken is the same as that
described referring to part (a) of Figure 278 and part (b) of Figure 278, and
therefore, the description thereof will be omitted. That is, the entire cam unit
3060 is integrally rotated in the direction of arrow RI by the driving force of the
development drive input gear 132.
[1359] The separation control member 196R (see Figure 25) temporarily
moves from the home position in the arrow W42 direction, and then immediately
moves in the arrow W41 direction to return to the home position. Then, as
shown in part (a) of Figure 277 and part (b) of Figure 277, the movable member
152R is pressed by the separation control member 196R to rotate in the direction
of the arrow BA. Then, in interrelation with the rotation of the movable
member 152R, the stopper link 3041 and the link cam 3042 rotate, and at the
same time, the stopper 3044 moves in a direction of approaching to the cam 3065
against the urging force of the link spring 3043. This is because the abutment
portion 3044c of the stopper 3044 slides on the second flank surface 3042g and
on the slip preventing portion 3042e of the link cam 3042 to abut to the contact
surface 3042c.
[1360] The cam 3065 having rotated in the direction of arrow RI by the
driving force of the development drive input gear 132 rotates through 180 degrees
from the second rotational position shown in part (a) of Figure 279 and part (b)
of Figure 280 to reach the first rotational position to abut to the stopper 3044.
As shown in part (a) of Figure 263, when the cam 3065 rotates from the second
rotational position to the first rotational position, the cam surface 3065a is separated from the contact portion 3028d of the development cover member 3028.
By this, the developing unit 3009 swings from the separated position to the
developing position by the urging force of the development pressing spring 134
(see Figure 34) and the driving torque received by the development coupling
portion 132a from the image forming apparatus main assembly 170.
[1361] As described above, in this embodiment, the driving force for rotating
the cam 3065 in the direction of the arrow RI1 is obtained from the driving force
of the development coupling portion 132a which rotates only in one direction.
In other words, the cam 3065 is rotatable from the second rotational position to
the first rotational position by such a received force that the development
coupling portion 132a is rotated in the arrow V2 direction, and also it is rotatable
from the first rotational position to the second rotational position by such a
received force that the development coupling portion 132a is rotated in the arrow
V2 direction. The cam 3065 rotates only in one direction, that is, in the
direction of the arrow RIO, by such a received force that the development
coupling portion 132a is rotated in the direction of the arrow V2. And, the
separation control member 196R moving to rotate the movable member 152R, the
stopper 3044 of the link unit 3040 is engaged with or is separated from the cam
3065 to position the cam 3065 at thefirst rotational position or the second
rotational position. Therefore, a drive source exclusively for rotating the cam
3065 is not necessary, and the cost can be reduced accordingly. In addition,
since the cam 3065 is rotated by using the driving of the development drive input
gear 132 which rotates unidirectionally, the structure can be simplified as
compared with a structure which requires forward rotation driving and reverse
rotation driving mechanisms.
[1362] The cam 3065 stably holds, in the first rotation position (the position
shown in part (a) of Figure 263), the developing unit 3009 at the developing position, and stably holds, in the second rotation position (the position shown in part (b) of Figure 263), the developing unit 3009 at the separation position. In this manner, the developing unit 3009 is swung between the developing position and the separation position by the cam 3065, and thus mechanical reliability is high and the durability can be improved.
[1363] Further, since the cam 3065 is driven by the driving force of the
development drive input gear 132 and the separation control member 196R is
moved to switch the position of the stopper 3044, the torque required for the
movement of the separation control member 196R can be reduced. Therefore,
the drive source such as a motor for driving the separation control member 196R
can be downsized and the cost can be reduced, and in addition, the rigidity
required for the separation control member 196R and the movable member 152R
can be reduced.
[1364] Next, Embodiment 31 will be described, referring to Figure 281 to part
(c) of Figure 296. In this embodiment, structures and operations different from
those of Embodiment 1 described above will be described, and members
including similar structures and functions are assigned the same reference
numerals, and the description thereof will be omitted. In this embodiment, in
place of the spacer 151R of Embodiment 1, the developing unit 3109 is held at
the developing position or the separation position by a holding member 3120.
In this embodiment, the movable member 152R is also provided in the
developing unit 3109.
[Overall Structure]
[1365] First, an overall structure of the process cartridge 3100 as a cartridge
will be described. Figure 281 is a perspective view illustrating the holding
member 3120 and the separation spring 3140. Figure 282 is a cross-sectional
view taken along aline 265A-265A of Figure 281. Figures 283 and 284 are exploded perspective views illustrating a drive-side cartridge cover member 116, a development cover member 128, a holding member 3120 and a separation spring 3140.
[1366] As shown in Figures 281 and 282, the process cartridge 3100 according to this embodiment includes a drum unit 108 and a developing unit 3109 which is
rotatable with respect to the drum unit 108. The developing unit 3109 as a
second unit includes a developing roller 106, and the developing roller 106 has a
metal core 106c made of a metal material and a rubber portion 106d fixed to the
outer peripheral surface of the metal core 106c. A holding member 3120 is
rotatably supported at an end portion 106e of the metal core 106c.
[1367] As shown in Figures 283 and 284, the drive-side cartridge cover member 116 covers the drive-side surface of the developing unit 3109, and
supports the development cover member 128 rotatably about the swing axis K of
the developing unit 3109. The developing roller 106 rotates in a direction of
arrowR21. The metal core 106c of the developing roller 106 is rotatably
supported by the drive-side bearing 126 of the developing unit 3109, and the
developing roller gear 131 is fixed to the metal core 106c. The developing
roller gear 131 is in meshing engagement with a development drive input gear
132 (see Figure 15) which receives a driving torque from the image forming
apparatus main assembly 170 by the development coupling portion 132a. The
development coupling portion 132a (see part (a) of Figure 263) as a driving force
receiving portion of the development drive input gear 132 is rotatable in the
direction of the arrow V2 as a predetermined direction by receiving a driving
force for rotationally driving the developing roller 106.
[Structure of Holding Member and Separation Spring]
[1368] Next, the structures of the holding member 3120 and the separation spring 3140 will be described in detail. The holding member 3120 as a holding portion regulates the relative position between the drum unit 108 and the developing unit 3109, and is structured to be rotatable between a separation holding position (position shown in Figure 281) a 1st position for holding the developing unit 3109 at the separation position by the drum unit 108 and an abutment holding position (position shown in part (a) of Figure 286) as a second position for holding the developing unit 3109 at the developing position by the drum unit 108. The holding member 3120 is provided with a hole portion 3120a having an oblong hole shape, a projection 3120b projecting outward in the radial direction, and a cylindrical portion 3120c extending in the axial direction. The end portion 106e of the metal core 106c penetrates through the hole portion
3120a. The hole portion 3120a has a friction surface 3120d and an opposing
surface 3120e at an inner peripheral surface thereof. The friction surface 3120d
and the opposing surface 3120e face each other in the extending direction of the
oblong hole-shaped hole portion 3120a, and the friction surface 3120d is closer to
the projection 3120b than the opposing surface 3120e.
[1369] A coil-shaped support portion 3140a of the separation spring 3140 is rotatably supported by the cylindrical portion 3120c, and a fixing portion 3140b
projecting outward in the radial direction from the support portion 3140a is fixed
to a spring fixing portion 3120f provided in the projection 3120b of the holding
member 3120. A support portion 3140c projecting outward in the radial
direction from the support portion 3140a is supported by a spring support portion
128f provided in the development cover member 128. The separation spring
3140 as an urging portion urges the holding member 3120.
[1370] As shown in Figure 281, the projection 3120b of the holding member 3120 has a holding surface 3120g provided at an end portion in the extending
direction of the hole portion 3120a, a locking surface 3120h on the downstream
side in the arrow R21 direction of the projection 3120b, and a locking surface
3120i on the upstream side in the arrow R21 direction of the projection 3120b.
The development cover member 128 is formed with a locking surface 128i which
can be contacted by the locking surface 3120i.
[1371] The drive-side cartridge cover member 116 includes a held portion
116g which can contact the holding surface 3120g, a locked portion 116h which
faces the locking surface 3120h, and a locked portion 116i which can face the
locking surface 3120i. The locked portions 116h and 116i face each other with
a gap equal to or larger than the width of the projection 3120b in the
circumferential direction.
[1372] The angle formed by the fixing portion 3140b and the support portion
3140c of the separation spring 3140 is approximately 90 to 120. In the state
that the separation spring 3140 is assembled to the holding member 3120 and the
development cover member 128, the support portion 3140c of the separation
spring 3140 is charged in a state of being urged in the direction of the arrow R21.
[Operations of the holding member and the separation spring]
[1373] Next, the operations of the holding member 3120 and the separation
spring 3140 will be described. Part (a) of Figure 285 is a side view illustrating
the force acting on the holding member 3120 and the separation spring 3140 in
the state that the driving force is not imparted to the development drive input gear
132 from the image forming apparatus main assembly 170.
[1374] As shown in part (a) of Figure 285, the separation spring 3140 is
charged such that the fixing portion 3140b is urged in the direction of arrow R22,
and the support portion 3140c is urged in the direction of arrow R21. Therefore,
a force F41 acts from the fixing portion 3140b to the spring fixing portion 3120f
of the holding member 3120. In addition, the support portion 3140c receives a
force pressing the spring support portion 128f, so that a force F42 acts on the
cylindrical portion 3120c of the holding member 3120 from the support portion
3140a. Further, a pressing force F40 is applied to the metal core 106c of the
developing roller 106 by the urging force of the development pressing spring 134
(see Figure 34).
[1375] The force F41 acts on the holding member 3120 to rotate in the
direction of the arrow R22, but the holding member 3120 is constrained from
rotating in the direction of the arrow R22 by the locking surface 3120i abutting
against the locking surface 128i of the development cover member 128. In
addition, the force F42 and the pressing force F40 act as forces in a direction in
which the holding member 3120 approaches to the held portion 116g of the drive
side cartridge cover member 116, but the movement of the holding member 3120
is restricted by the holding surface 3120g abutting against the held portion 116g.
In this manner, the holding member 3120 is in a state of holding back against the
held portion 116g of the drive-side cartridge cover member 116, by which the
developing roller 106 and the photosensitive drum 104 are separated from each
other, and the developing unit 3109 is held at the separated position.
[1376] Part (b) of Figure 285 is a side view illustrating a state in which the
driving force is inputted to the development drive input gear 132 in a state in
which the developing unit 3109 is placed at the separation position. The holding
surface 3120g of the holding member 3120 receives the reaction force NN 1 from
the held portion 116g. Here, the holding member 3120 receives a force F42 in a
direction opposite to the reaction force NN1 from the separation spring 3140, but
the force F42 is sufficiently smaller than the reaction force NN1.
[1377] The reaction force NN1 produces a reaction force -NN1 from the metal
core 106c against the friction surface 3120d of the holding member 3120. When
the driving force is inputted to the development drive input gear 132 in a state
that the developing unit 3109 is placed at the separation position, the metal core
106c rotates in the direction of arrow R21. Then, a frictional force F43 due to the reaction force -NN1 is generated between the metal core 106c as the rotation shaft and the friction surface 3120d of the holding member 3120. The frictional force F43 produces a rotational force C43 that rotates in the direction of the arrow
R21 in the holding member 3120. In addition, a force F41 resulting from the
urging force of the separation spring 3140 described above acts on the holding
member 3120, and the force F41 acts on the holding member 3120 as a force for
rotating in the direction of the arrow R22. That is, the holding member 3120
receives the rotational force C43 as a first moment in the first direction (arrow
R21 direction) which urges the holding member 3120 from a separation holding
position toward an abutment holding position, and receives the force F41 as the
second moment in the second direction (arrow R22 direction) opposite to the first
direction.
[1378] Therefore, when the rotational force C43 becomes larger than the force
F41, the holding member 3120 begins to rotate in the direction of the arrow R21.
In this embodiment, a friction coefficient of the friction surface 3120d, a spring
pressure of the development pressing spring 134, and a spring pressure of the
separation spring 3140 are selected such that the holding member 3120 starts to
rotate in the direction of the arrow R21 by the inputting of the driving force to the
development drive input gear 132.
[1379] Part (a) of Figure 286 is a side view illustrating the action of the
holding member 3120 and the separation spring 3140 in a state in which the
developing unit 3109 is at the developing position. By the holding member
3120 rotating in the direction of the arrow R21, the contact between the holding
surface 3120g of the holding member 3120 and the held portion 116g is broken.
The holding member 3120 can restrict rotation in the direction of the arrow R21
by the locking surface 3120h abutting against the locked portion 116h.
[1380] In addition, the holding member 3120 moves toward the second held portion 116j of the drive-side cartridge cover member 116 by the pressing forces
F40 and the force F42. By this, the holding surface 3120g of the holding
member 3120 is bought into abutment against the second held portion 116j. At
this time, the holding member 3120 moves so that the metal core 106c is
positioned substantially at a central portion of the hole portion 3120a. In this
manner, the state in which the holding member 3120 is held back against the held
portion 116g of the drive-side cartridge cover member 116 is released, by which
the developing roller 106 is brought into contact with the photosensitive drum
104, so that the developing unit 3109 is held at the developing position.
[1381] In a state in which the metal core 106c is placed substantially at the
center portion of the hole portion 3120a, the metal core 106c and the friction
surface 3120d of the hole portion 3120a are separated from each other, and
therefore, the frictional force F43 described with reference to part (b) of Figure
285 is zero. The metal core 106c and the hole portion 3120a are slightly in
contact with each other, that is, at the surfaces other than the friction surface
3120d and the opposing surface 3120e, and therefore, the rotational force C43 of
the holding member 3120 decreases to C43' (<C43). By this, the rotational
force C43' becomes smaller than the force F41 tending to rotate the holding
member 3120 in the direction of the arrow R22, with the result that the holding
member 3120 rotates in the direction of the arrow R22. Then, the holding
member 3120 is constrained from rotating in the direction of the arrow R22 by
the locking surface 3120i abutting against the locked portion 116i.
[1382] Part (b) of Figure 286 is a perspective view illustrating the action of the
holding member 3120 and the separation spring 3140 in a state in which the
developing unit 3109 is placed at a position further away from the drum unit 108
than in the separation position (hereinafter, referred to as a second separation
position). The developing unit 3109 is placed at the second separation position by the separation control member 196R pressing the movable member 152R.
And, by the force F42 caused by the spring force of the separation spring 3140
acting on the holding member 3120, the holding member 3120 is moved in a
direction of approaching to the held portion 116g of the drive-side cartridge cover
member116. Then, the metal core 106c is brought into contact to the opposing
surface 3120e of the holding member 3120.
[1383] A reaction force NN 2 from the metal core 106c acts on the holding
member 3120, and the metal core 106c rotates, thereby generating a frictional
force F44. The frictional force F44 generates a rotational force C44 in the
direction of the arrow R21 in the holding member 3120. The force F41
described above acts on the holding member 3120 and the force F41 acts on the
holding member 3120 as a force for rotation in the direction of the arrow R22.
That is, the holding member 3120 receives the rotational force C44 as a third
moment in the first direction (arrow R21 direction) and the force F41 as a
moment in the second direction (arrow R22 direction) opposite to the first
direction.
[1384] In this embodiment, the force F41 is set to be larger than the rotational
force C44, and the holding member 3120 rotates in the direction of the arrow R22.
Here, in a state that the developing unit 3109 is moved from the developing
position to the second separation position, that is, toward the separation position,
and the development coupling portion 132a receives the driving force, the force
F41 is larger than the rotational force C44. And, by the locking surface 3120i of
the holding member 3120 abutting against the locking surface 128i of the
development cover member 128, the rotation of the holding member 3120 in the
direction of the arrow R22 is restricted. At this time, the holding surface 3120g
faces the held portion 116g.
[1385] Thereafter, when the movable member 152R is released from the separation control member 196R, the holding surface 3120g of the holding member 3120 is brought into abutment to the held portion 116g by the action of the urging force of the development pressing spring 134 and the driving force of the development drive input gear 132, and the state returns to that shown in part
(a) of Figure 285.
[1386] As described above, in this embodiment, the driving force for rotating
the holding member 3120 in the direction of the arrow R21 is obtained from the
driving force of the development drive input gear 132 which rotates only in one
direction. That is, the holding member 3120 is rotated from the separation
holding position where the developing unit 3109 is held at the separation position
to the contact holding position where the developing unit 3109 is held at the
developing position, by the driving force of the development drive input gear 132.
For this reason, a drive source exclusively for rotating the holding member 3120
is not necessary, and the cost can be reduced, accordingly.
[1387] When the developing unit 3109 is to be swung from the separation
position to the developing position, the holding member 3120 is automatically
rotated from the separation holding position to the contact holding position only
by driving the development drive input gear 132. Therefore, a driving force for
driving the separation control member 196R is not necessary, and energy saving
can be achieved. In addition, when the developing unit 3109 is to be swung
from the developing position to the separation position, the holding member 3120
is rotated from the contact holding position to the separation holding position by
the spring force of the separation spring 3140, so that energy saving can be
achieved. Further, since the holding member 3120 is rotated by using the
driving of the development drive input gear 132 that rotates only in one direction,
the structure can be simplified as compared with a structure which requires both
of forward rotation driving and reverse rotation driving mechanism.
[Structure of Delaying Mechanism]
[1388] When the drive is inputted to the development drive input gear 132, the
holding member 3120 quickly rotates from the separation holding position to the
contact holding position. Therefore, the developing roller 106 of the developing
unit 3109 comes into contact with the photosensitive drum 104 immediately after
the drive is inputted to the development drive input gear 132.
[1389] A service life of the developing roller 106 is longer if it is separated
from the photosensitive drum 104 as much as possible except for the duration in
which the electrostatic latent image on the photosensitive drum 104 is developed.
In view of this, in this embodiment, a delaying mechanism 3200 for delaying the
instance at which the developing roller 106 starts to rotate after the input of the
drive to the development driving input gear 132 is provided, and the service life
of the developing roller 106 is further extended.
[1390] Hereinafter, the structure of the delaying mechanism 3200 will be
described in detail. Figures 287 and 288 are exploded perspective views
illustrating the delaying mechanism 3200. Figure 289 is a sectional view
illustrating the delaying mechanism 3200. As shown in Figures 287 to 289, the
development drive input gear 132 includes a development coupling portion 132a
to which drive is inputted from the image forming apparatus main assembly 170,
and an output gear 132b which meshes with the developing roller gear 131. The
delaying mechanism 3200 is disposed between the development coupling portion
132a and the output gear 132b, and is structured to transmit or shut the driving
force of the development coupling portion 132a to the output gear 132b.
[1391] The delaying mechanism 3200 is provided in a drive transmission path
extending from the development coupling portion 132a to the developing roller
106. The delaying mechanism 3200 includes a lever 3210, a clutch 3220, and a
spring 3230. The development coupling portion 132a includes a cylindrical portion 132c extending in the axial direction D40, and a projecting portion 132d and a shaft portion 132e provided on one end surface of the cylindrical portion
132c in the axial direction D40 and projecting toward the output gear 132b. The
projecting portion 132d extends in the radial direction, and the shaft portion 132e
extends in the axial direction D40. The shaft portion 132e is rotatably supported
by the output gear 132b. The position of the development coupling portion 132a
in the axial direction D40 is regulated by the development cover member 128.
[1392] The lever 3210 includes a cylindrical support portion 3211 rotatably
supported by the cylindrical portion 132c of the development coupling portion
132a, and a locking portion 3212 projecting radially outward from an outer
peripheral surface of the support portion 3211. The clutch 3220 includes a
recess 3221 rotatably supported by the cylindrical portion 132c of the
development coupling portion 132a, an engagement groove 3222 formed in a
bottom surface of the recess 3221, and a through hole 3223 formed in a central
portion of the engagement groove 3222. The shaft portion 132e of the
development coupling portion 132a penetrates the through hole 3223. The
clutch 3220 has projecting portions 3224 and 3225 projecting outward in the
radial direction, and the projecting portions 3224 and 3225 are disposed at
positions of 180-degree phase difference.
[1393] The spring 3230 is a compression coil spring, and is compressed in the
axial direction D40 between the clutch 3220 and the output gear 132b. The
spring 3230 is fixed to the clutch 3220 and the output gear 132b. The output
gear 132b is provided with groove portions 132f and 132g having sector shapes
into which the projecting portions 3224 and 3225 of the clutch 3220 can enter,
respectively. The projections 3224 and 3225 are provided so as to be rotatable
by a predetermined angle in the state that they are in the groove portions 132f and
132g, respectively.
[1394] Part (a) of Figure 290 is a perspective view illustrating the delaying
mechanism 3200 in a state in which no drive is inputted to the development
coupling unit 132a. Part (b) of Figure 290 is a perspective view illustrating the
clutch 3220, the spring 3230, and the output gear 132b in the state that no drive is
inputted to the developing coupling unit 132a. Figure 291 is a perspective view
illustrating a drive transmission state in which drive is inputted to the
development coupling portion 132a and the drive of the development coupling
portion 132a is transmitted to the output gear 132b.
[1395] As shown in part (a) of Figure 290 and part (b) of Figure 290, in the
state that no drive is input to the development coupling portion 132a, the
projecting portion 132d of the development coupling portion 132a is not engaged
with the engagement groove 3222 of the clutch 3220. In other words, the
projecting portion 132d is out of phase with respect to the engagement groove
3222 in the rotational direction and is offset with respect to the engagement
groove 3222 in the axial direction D40 of the delaying mechanism 3200.
[1396] The projecting portions 3224 of the clutch 3220 is spaced, in the
direction of the arrow R31, from the one end surface 132fl of the groove portion
132f. Similarly, the projecting portions 3225 of the clutch 3220h is spaced, in
the direction of the arrow R31, from the one end surface 132gl of the groove
portion 132g.
[1397] When the development coupling portion 132a rotates in the direction of
arrow R31 until the projecting portion 132d and the engagement groove 3222 are
in phase, the clutch 3220 slides toward the development coupling portion 132a in
the axial direction D40 by the urging force of the spring 3230. Then, the
projecting portion 132d and the engagement groove 3222 are brought into
engagement with each other. And, by the engagement between the projecting
portion 132d and the engagement groove 3222, the development coupling portion
132a and the clutch 3220 rotate integrally. At this time, the lever 3210 remains
at rest, that is, does not rotate.
[1398] By rotation of the clutch 3220 in the direction of the arrow R31, the
projection portion 3224 is brought into contact with the one end surface 132f1, as
illustrated in Figure 291, and the projection portion 3225 is brought into contact
with the one end surface 132gl. By this, the driving force of the development
coupling portion 132a is transmitted to the output gear 132b by way of the clutch
3220, and the delaying mechanism 3200 becomes in the driving transmission
state.
[1399] Figure 292 is a perspective view illustrating an arrangement
relationship between the lever 3210 and the drive-side cartridge cover member
116 and the development cover member 128. Part (a) of Figure293 is a
perspective view illustrating the position of the lever 3210 when the developing
unit 3109 is placed in the developing position. Part (b) of Figure 293 is a
perspective view illustrating the position of the lever 3210 when the developing
unit 3109 is placed in the separation position.
[1400] As shown in Figures 287 to 288 and Figure 292, the development
cover member 128 is provided with a cut-away portion 128r into which the
locking portion 3212 of the lever 3210 is inserted. The cut-away portion 128r
includes a first locking portion 128s, a second locking portion 128u, and has an
inclined surface 128t which connects these first locking portion 128s and second
locking portion 128u. The first locking portion 128s and the second locking
portion 128u are provided so that the locking portion 3212 of the lever 3210 can
be locked, and the second locking portion 128u is provided on the side closer to
the development coupling portion 132a in the axial direction D40 than the first
locking portion 128s.
[1401] The inclined surface 128t is provided so as to incline with respect to the axial direction D40, and smoothly guides the locking portion 3212 of the lever 3210 between the first locking portion 128s and the second locking portion
128u.
[1402] The drive-side cartridge cover member 116 is provided with a locking
groove 116s for locking the locking portion 3212 of the lever 3210. Whenthe
locking portion 3212 is locked in the locking groove 116s in the directions of the
arrows R31 and R32, the relative position of the lever 3210 in the directions of
the arrows R31 and R32 with respect to the drive-side cartridge cover member
116 does not change. The locking portion 3212 is slidable in the axial direction
D40 with respect to the locking groove 116s.
[1403] Since the development cover member 128 swings integrally with the
developing unit 3209, the development cover member 128 rotates in the
directions of arrows R31 and R32 relative to the lever 3210 when the developing
unit 3209 swings between the developing position and the separation position.
[Operation of Delaying Mechanism]
[1404] Next, the operation of the delaying mechanism 3200 will be described
in detail. Part (a) of Figure 294 is a sectional view illustrating the delaying
mechanism 3200 in a state in which no drive is inputted to the development
coupling unit 132a. Part (b) of Figure 294 is perspective views illustrating the
delaying mechanism 3200 in a state in which no drive is inputted to the
development coupling unit 132a. Part (c) of Figure 294 is a perspective view
illustrating a state in which the phases of the projecting portion 132d and the
engagement groove 3222 of the development coupling portion 132a are aligned.
Part (d) of Figure 294 is a perspective view illustrating a state in which the clutch
3220 is slid in the axial direction D40.
[1405] As shown in part (a) of Figure 294 and part (b) of Figure 294, in the
state that no drive is inputted to the development coupling portion 132a, the projecting portion 132d of the development coupling portion 132a is out of engagement with the engagement groove 3222 of the clutch 3220. As shown in part (b) of Figure 294 and part (c) of Figure 294 , when the drive is input to the development coupling portion 132a and the phases of the projecting portion 132d and the engagement groove 3222 are aligned, the clutch 3220 is slid toward the development coupling portion 132a in the axial direction D40 by the urging force of the spring 3230. Then, as shown in part (d) of Figure 294, the projecting portion 132d and the engagement groove 3222 engage with each other. And, the clutch 3220 is brought into contact with the lever 3210 in the axial direction
D40.
[1406] Part (a) of Figure 295 is a perspective view illustrating a state
immediately before the clutch 3220 starts to rotate. Part (b) of Figure 295 is a
perspective view illustrating the delaying mechanism 3200 in the drive
transmission state. As shown in part (a) of Figure 295 and part (b) of Figure
295, before the clutch 3220 starts to rotate, the projections 3224 and 3225 of the
clutch 3220 are spaced, in the direction of the arrow R31, from one end surfaces
132fl and 132gl, respectively.
[1407] By the rotation of the clutch 3220 in the direction of the arrow R31, as
shown in part (c) of Figure 295, the projection portion 3224 is brought into
contact with the one end surface 132f1, and the projection portion 3225 is
brought into contact with the one end surface 132gl. By this, the driving force
of the development coupling portion 132a is transmitted to the output gear 132b
by way of the clutch 3220, so that the delaying mechanism 3200 is brought into
the driving transmission state. Here, the clutch 3220 rotates relative to the
output gear 132b in the direction of the arrow R31 by a predetermined angle by
the time at which the projections 3224 and 3225 come into contact with the end
surfaces 132fl and 132gl, respectively. Since the spring 3230 is fixed to the clutch 3220 and the output gear 132b, the clutch 3220 rotates by a predetermined angle in the direction of the arrow R31, by which the spring 3230 is twisted and the elastic force is charged.
[1408] When the delaying mechanism 3200 becomes in the drive transmission
state, the developing roller 106 is rotated by the output gear 132b, and the holding
member 3120 is rotated from the separation holding position to the contact
holding position (see Figure 286). By this, the developing unit 3109 swings
from the separated position to the developing position. At this time, since the
lever 3210 is locked by the locking groove 116s of the drive-side cartridge cover
member 116, the attitude does not change. On the other hand, since the
development cover member 128 that swings integrally with the developing unit
3109 swings with respect to the drive-side cartridge cover member 116, the lever
3210 rotates relative to the development cover member 128. Thus,thelocking
portion 3212 of the lever 3210 is locked with the second locking portion 128u as
shown in part (a) of Figure 293.
[1409] When the developing unit 3109 swings from the developing position to
the separation position, the separation control member 196R first presses the
movable member 152R to position the developing unit 3109 at the second
separation position. At this time, the lever 3210 is locked by the locking groove
116s of the drive-side cartridge cover member 116, and therefore, the attitude
thereof does not change. On the other hand, since the development cover
member 128 which swings integrally with the developing unit 3109 swings with
respect to the drive-side cartridge cover member 116, the lever 3210 rotates
relative to the development cover member 128. Thus, as shown in part (b) of
Figure 293, the locking portion 3212 of the lever 3210 is locked with the first
locking portion 128s by ascending the inclined surface 128t from the second
locking portion 128u.
[1410] Therefore, the lever 3210 moves away from the development coupling
portion 132a in the axial direction D40. Then, as illustrated in part (b) of Figure
296, by the lever 3210 pressing the clutch 3220, the clutch 3220 also moves in a
direction away from the development coupling portion 132a in the axial direction
D40. By this, the engagement between the projecting portion 132d of the
development coupling portion 132a and the engagement groove 3222 of the
clutch 3220 is broken, and as illustrated in part (c) of Figure 296, the clutch 3220
is rotated in the direction of arrow R32 by the elastic force charged by the spring
3230. Then, the phases of the projecting portion 132d and the engagement
groove 3222 of the clutch 3220 become out of phase, and the delaying
mechanism 3200 returns to the initial state as illustrated in part (b) of Figure 294.
[1411] As described above, the delaying mechanism 3200 can extend the time
duration from the inputting of the drive from the image forming apparatus main
assembly 170 to the development coupling portion 132a to the rotation of the
holding member 3120 from the separation holding position to the contact holding
position. In other words, the delaying mechanism 3200 as a transmission
mechanism transmits the driving force received by the development coupling unit
132a to the developing roller 106 after a predetermined time elapses. The
holding member 3120 does not start rotating until at least a time duration
obtained by adding the time duration from the time at which the drive is inputted
to the development coupling portion 132a to the time at which the projecting
portion 132d of the development coupling portion 132a and the engagement
groove 3222 of the clutch 3220 are in phase with each other and the time until the
projecting portions 3224 and 3225 of the clutch 3220 are brought into contact
with the one end surfaces 132fl and 132gl of the output gear 132b. This can
shorten the time in which the developing roller 106 is in contact with the
photosensitive drum 104, and can increase the service life of the developing roller
106. <Modification of Embodiments 30 to 31>
[1412] In Embodiment 30, the cam drive gear 3061 rotates in the direction of
the arrow RI by receiving the driving force of the development coupling portion
132a to rotationally drive the developing roller 106, but the present invention is
not limited to such an example. For example, the cam drive gear 3061 may be
structured to rotate in the direction of the arrow RI by receiving a driving force
for rotationally driving the photosensitive drum 104 of the coupling member 143.
[1413] In addition, in Embodiment 30, the stopper 3044 is structured to move
in interrelation with the movable member 152R, but the present invention is not
limited to such an example. For example, the stopper 3044 may be structured to
be moved by another member or actuator.
[1414] In Embodiment 30, the used clutch 3090 is a spring clutch including
the coil spring 3063, but the present invention is not limited to such an example.
For example, other clutches such as a meshing clutch and an electromagnetic
clutch may be applied instead of the clutch 3090.
[1415] In Embodiment 31, the holding member 3120 is rotated in the direction
of the arrow R21 by receiving the driving force for rotationally driving the
developing roller 106 of the development coupling portion 132a, but the present
invention is not limited to such an example. For example, the holding member
3120 may be structured to be rotated in the direction of the arrow R21 by
receiving a driving force for rotationally driving the photosensitive drum 104 of
the coupling member 143.
[1416] The delaying mechanism 3200 of Embodiment 31 can delay a time by
the duration obtained by adding the time period until the projecting portion 132d
of the development coupling portion 132a and the engagement groove 3222 of
the clutch 3220 are in phase with each other and the time period until the projections 3224 and 3225 of the clutch 3220 come into contact with the one end surfaces 132f1, 132gl of the output gear 132b, respectively, but the duration may be provided by only one of them. The delay time may be changed as appropriate by the structure.
[1417] In Embodiments 30 to 28, the cam 3065 and the holding member 3120
are rotatably supported by the developing unit, but the present invention is not
limited to such an example. For example, the cam 3065 and the holding
member 3120 may be rotatably supported by the drum unit.
[1418] The above-described embodiments may be combined as appropriate.
For example, the pressing unit 2780 of Embodiment 30 may be applied to the
process cartridge of Embodiment 9.
<EMBODIMENT 32>
[1419] Next, referring to part (a) of Figure 297 to part (b) of Figure 326,
Embodiment 32 will be described. In this embodiment, the structure and
operation different from those of Embodiment 1 will be described, and the same
reference numerals are assigned to the members having similar structures and
functions, and the description thereof will be omitted.
[Overall structure]
[1420] First, the overall structure of a process cartridge 6100 as a cartridge
according to Embodiment 32 will be described. Part (a) of Figure 297 is a
perspective view of a process cartridge 6100 as viewed from the drive side, and
part (b) of Figure 297 is a perspective view of a developing unit 6109.
[1421] As shown in part (a) of Figure 297 and part (b) of Figure 297, the
process cartridge 6100 comprises a drum unit 108 including a photosensitive
drum 104 and a charging roller 105 (see Figure 3), a developing unit 6109
including a developing roller 106, and a drive side cartridge cover member 6116
and a non-drive side cartridge cover member 6117 which supports the drum unit
108 and the developing unit 6109. The photosensitive drum 104, the charging
roller 105, the developing roller 106, the drum unit 108, and the developing unit
6109 constitute a photosensitive member, a charging member, a developing
member, a first unit, and a second unit, respectively.
[1422] The developing unit 6109 is movable between a contact position
(developing position) and a separated position about a swing axis K relative to
the drum unit 108, and when the developing unit 6109 is positioned at the
developing position, the developing roller 106 of the process cartridge 6100 is
capable of depositing toner onto the photosensitive drum 104. The developing
roller 106 is disposed so as to be spaced from the photosensitive drum 104 by a
gap P (see part (b) of Figure 313) at the time when the developing unit 6109 is in
the separated position. As shown in Embodiment 2 (part (b) of Figure 44 and so
on), the structure may be such that at least a part of the developing roller 106 is
disposed away from the photosensitive drum 104. The photosensitive drum 104
and the developing roller 106 are supported so as to be rotatable about rotation
axes M1 and M2, respectively.
[Structure of Separation/Contact Mechanism 6150]
[1423] The structure in which the developing roller 106 separates from and
contacts the photosensitive drum 104 will be described in detail below. As
shown in part (b) of Figure 297, the developing unit 6109 includes the
separation/contact mechanism 6150R on the drive side and the separation/contact
mechanism 6150L on the non-drive side. Regarding the separation/contact
mechanism, the drive side separation/contact mechanism 6150R only will be
described in detail, but the non-drive side separation/contact mechanism 6150L
also has a similar mechanism. In addition, the separation/contact mechanisms
on the drive side and non-drive side have almost the same functions, and
therefore, the reference numerals of the members on the drive side are added with an R. On the non-drive side, the reference numerals of the members are the same as those on the drive side, and an L is added instead of R.
[1424] Figure 298 is a perspective view illustrating the drive side separation/contact mechanism 6150R. Part (a) of Figure 299 is a cross-sectional
view illustrating the separation/contact mechanism 6150R in a state that a pressed member 6152R is not pressed by the cartridge pressing mechanism 191 (see part
(a) of Figure 316). Part (b) of Figure 299 is a cross-sectional view illustrating
the separation/contact mechanism 6150R in a state that the pressed member
6152R is pressed by the cartridge pressing mechanism 191.
[1425] As shown in Figure 298, the separation/contact mechanism 6150R
includes a drive side bearing 6126, compression springs 6153R and 6163R, a
pressed member 6152R, a stepped gear 6161R, a movable member 6162R, a
holding member 6151R, and a development covering member 6128.
[1426] As will be described in detail hereinafter, as shown in part (a) of Figure 299 and part (b) of Figure 299, when the pressed member 6152R is pressed by the cartridge pressing mechanism 191 (see part (a) of Figure 316) and moves in the
ZB direction, the movable member 6162R moves in the ZB direction from the
standby position shown in part (a) of Figure 299 to the projecting position shown
in part (b) of Figure 299. At this time, the amount of movement of the pressed
member 6152R in the ZB direction is a movement amount D60, whereas the
amount of movement of the movable member 6162R in the ZB direction is a
movement amount D61 which is larger than the movement amount D60. This is
because the movement of the pressed member 6152R is accelerated by the
stepped gear 6161R. In this embodiment, the gear ratio between the large
diameter gear portion 6161Rb (see part (a) of Figure 303) and the small diameter
gear portion 6161Rc of the stepped gear 6161R is 2:1, and therefore, the
movement amount D61 is twice the movement amount D60.
[1427] Furthermore, when the movable member 6162R moves in the ZB
direction, the holding member 6151R is pressed in the ZB direction by way of the
compression spring 6153R, and the holding member 6151R is also moved in the
ZB direction. When the pressed member 6152R is moved in the -ZB direction
by the urging force of the compression spring 6163R, the movable member
6162R and the holding member 6151R also moves in the -ZB direction.
[1428] The ZB direction and the -ZB direction opposite to the ZB direction are
directions defined based on the developing unit 6109. In other words, the ZB
direction and the -ZB direction are the movement directions of the pressed
member 6152R, the movable member 6162R and the holding member 6151R,
and as the developing unit 6109 swings about the swing axis K between the
contact position (developing position) and the separated position, the relative
directions with respect to the horizontal direction (X1 direction and X2 direction)
and the vertical direction (ZI direction and Z2 direction) change.
[1429] In this embodiment, the directions perpendicular to the ZB direction
and the -ZB direction are defined as the XB direction and the -XB direction, and
the XB direction is the direction in which the developing unit 6109 moves away
from the drum unit 108. In addition, in the state that the developing unit 6109 is
placed in the separated position, the ZA direction in which the cartridge pressing
mechanism 191 (see part (a) of Figure 316) presses the pressed member 6152R is
substantially parallel to the ZB direction in which the pressed member 6152R, the
movable member 6162R, and the holding member 6151R move.
[1430] Part (a) of Figure 300 is a perspective view illustrating the
development covering member 6128, and part (b) of Figure 300 is a perspective
view illustrating the movable member 6162R. Part (a) of Figure 301 is a
perspective view illustrating the holding member 6151R, and part (b) of Figure
301 is another perspective view illustrating the holding member 6151R. Part (a) of Figure 302 is a perspective view illustrating the drive side bearing 6126, and part (b) of Figure 302 is a perspective view illustrating the pressed member
6152R. Part (a) of Figure 303 is a perspective view illustrating the stepped gear
6161R, and part (b) of Figure 303 is another perspective view illustrating the
stepped gear 6161R.
[1431] As shown in part (a) of Figure 300, the development covering member
6128 has movable member supporting surfaces 6128a and 6128b, holding
member supporting surfaces 6128c and 6128d, an abutment surface 6128e, and a
restricting surface 6128f. The movable member support surfaces 6128a, 6128b
are disposed opposite to each other and support the movable member 6162R so as
to be movable in the ZB direction. The holding member support surfaces 6128c,
6128d are disposed opposite to each other and support the holding member
6151R movably in the ZB direction. The movable member support surfaces
6128a, 6128b and the holding member support surfaces 6128c, 6128d extend in
the ZB direction.
[1432] The abutment surface 6128e is formed so as to connect the upstream,
in the ZB direction, ends of the holding member support surfaces 6128c and
6128d, and restricts movement of the holding member 6151R in the -ZB direction
by abutting against the holding member 6151R. The restricting surface 6128f
extends along the ZB direction and restricts the movement of the movable
member 6162R and the stepped gear 6161R in the Y2 direction. TheY2
direction and the Y1 direction opposite to the Y2 direction are directions parallel
to the axial direction of the swing axis K.
[1433] As shown in part (b) of Figure 300, the movable member 6162R is
formed in a generally L-shape as a whole. The movable member 6162R has
supported surfaces 6162Ra, 6162Rb, a locking portion 6162Rc, an abutment
surface 6162Rd, a rise restriction surface 6162Re, a rack gear 6162Rf, a spring seat 6162Rg, and a boss 6162Rh.
[1434] The supported surfaces 6162Ra and 6162Rb are supported by movable
member supporting surfaces 6128a and 6128b of the development covering
member 6128 so as to be movable in the ZB direction. The locking portion
6162Rc is formed to face in the Y1 direction, and by the locking portion 6162Rc
contacting the holding member 6151R arranged downstream in the Y1 direction,
the movement of the holding member 6151R in the Y2 direction is restricted.
By the holding member 6151R abutting against the abutment surface 6162Rd, the
movement of the holding member 6151Rin the ZB direction is restricted. By
the holding member 6151R abutting against the rise restriction surface 6162Re,
the movement of the holding member 6151R in the -ZB direction is restricted.
[1435] The rack gear 6162Rf is shown as a flat surface in part (b) of Figure
300, but has a plurality of teeth aligned in the ZB direction, and is in meshing
engagement the large diameter gear portion 6161Rb (see part (a) of Figure 303)
of the stepped gear 6161R. The spring seat 6162Rg is a surface facing
downstream in the ZB direction, and supports one end of the compression spring
6153R. A boss 6162Rh projects in the ZB direction from the spring seat
6162Rg, and one end of the compression spring 6153R is fitted around the boss
6162Rh.
[1436] As shown in part (a) of Figure 301 and part (b) of Figure 301, the
holding member 6151R includes a guided portion 6151Rd which extends in the
ZB direction and which is supported by the holding member support surfaces
6128c, 6128d of the development cover member 6128 movably in the ZB
direction, a holding portion 6151Rb which extends in the -XB direction from the
upstream end of the guided portion 6151Rd in the ZB direction, and a free end
portion 6151Rm which is provided at the downstream end of the holding member
6151R in the ZB direction.
[1437] A supported portion 6151Ra is provided at the downstream end, in the
XB direction, of the guided portion 6151Rd and the holding portion 6151Rb.
The supported portion 6151Ra contacts the holding member support surfaces
6128c of the development covering member 6128 in the state in which the
developing unit 6109 is placed at the separated position. The holding portion
6151Rb has a contact portion 6151Rc which is disposed at the downstream end in
the -XB direction. The contact portion 6151Rc is in contact with a contacted
surface 6116q (see part (a) of Figure 313) of the drive side cartridge cover
member 6116 in the state in which the developing unit 6109 is placed at the
separated position. That is, the holding portion 6151Rb is a portion which
connects the supported portion 6151Ra and the contact portion 6151Rc with each
other, and has stiffness sufficient to be sandwiched between the drum unit 108
and the developing unit 6109 so as to maintain the developing unit 6109 at the
separated position (retracted position).
[1438] In addition, the holding portion 6151Rb restricts the relative position
between the drum unit 108 and the developing unit 6109, and is movable between
a separation holding position as a first position for holding the developing unit
6109 in the separated position, and a separation release position as a second
position for holding the developing unit 6109 in the developing position.
[1439] The free end portion 6151 Rm as a projecting portion can pop out
beyond the first frame of the drum unit 108 and the second frame of the
developing unit 6109 at least in a direction away from the rotation axis of the
developing roller 106. The free end 615IRm is provided with a contact force
receiving surface 6151Rg and a separating force receiving surface (separating
force receiving portion) 6151Rh. The contact force receiving surface 6151Rg
and the separating force receiving surface 6151Rh are provided at the
downstream end, in the ZB direction, of the free end portion 6151Rm, and are inclined surfaces inclined with respect to the ZB direction and the XB direction, respectively. More specifically, the contact force receiving surface 6151Rg is a surface which inclines toward the -XB direction as it goes in the ZB direction, and the separating force receiving surface 6151Rh is a surface which inclines toward the ZB direction as it goes in the XB direction. In other words, as viewed along the rotation axis M1 of the photosensitive drum 104, the contact force receiving surface 6151Rg is inclined so as to be away from the rotation axis
M1 in the ZB direction as goes approaching the rotation axis M1 in the XB
direction which is a direction perpendicular to the ZB direction.
[1440] The holding member 6151R further includes a locked portion 6151Re, an abutted surface 6151Rf, a spring seat 6151Rj, and a boss 6151Rk. The
locked portion 6151Re is locked by the locking portion 6162Rc of the movable
member 6162R, so that the movement thereof in the Y2 direction is restricted,
and it abuts against the rise restriction surface 6162Re, by which the movement
thereof in the -ZB direction is restricted. The abutted surface 6151Rf is abutted by the abutment surface 6162Rd of the movable member 6162R to restrict the
movement in the ZB direction.
[1441] The spring seat 6151Rj is a surface facing downstream in the -ZB direction, and supports the other end of the compression spring 6153R. From
the spring seat 6151Rj, a boss 615IRk projects in the -ZB direction, and the other
end of the compression spring 6153R is fitted around the boss 6151Rk.
[1442] As shown in part (a) of Figure 302, the drive side bearing 6126 has support surfaces 6126a, 6126b, abutment surfaces 6126c, 6126d, a spring seat
6126e, a stepped gear support shaft 6126f, a development cover member 6128,
and second restricting surfaces 6126h, 6126i. The support surfaces 6126a and
6126b support the pressed member 6152R so as to be movable in the ZB
direction. The abutment surfaces 6126c and 6126d restrict the movement of the pressed member 6152R in the -ZB direction by being abutted by the pressed member 6152R. The spring seat 6126e supports one end of the compression spring 6163R.
[1443] The stepped gear support shaft 6126f extends in the Y2 direction from
the development cover member 6128, and supports the stepped gear 6161R
rotatably about a rotation axis M8. The development cover member 6128
restricts the movements of the pressed member 6152R and the stepped gear
6161R in the Y1 direction. The second restriction surfaces 6126h and 6126i
restrict the movement of the movable member 6162R in the Y1 direction.
[1444] As shown in part (b) of Figure 302, the pressed member 6152R has
supported surfaces 6152Ra, 6152Rb, abutted surfaces 6152Rc, 6152Rd, a spring
seat 6152Re, a rack gear 6152Rf, and a pressed surface 6152Rg. The supported
surfaces 6152Ra, 6152Rb are supported by support surfaces 6126a, 6126b of the
drive side bearing 6126 so as to be movable in the ZB direction. The abutted
surfaces 6152Rc, 6152Rd abut against abutment surfaces 6126c, 6126d of the
drive side bearing 6126, so that the movement in the -ZB direction is restricted.
The spring seat 6152Re supports the compression spring 6163R between itself
and the spring seat 6126e of the drive side bearing 6126.
[1445] The rack gear 6152Rf is shown as a flat surface in part (b) of Figure
302, but has a plurality of teeth aligned in the ZB direction, and is in meshing
engagement with the small diameter gear portion 6161Rc of the stepped gear
6161R (see part (a) of Figure 303). The pressed surface 6152Rg is a surface
which receives a pressing force from the cartridge pressing mechanism 191 (see
part (a) of Figure 316).
[1446] As shown in part (a) of Figure 303 and part (b) of Figure 303, the
stepped gear 6161R is provided with a support hole 6161Ra centered on the
rotation axis M8, a large diameter gear portion 6161Rb, and a small diameter gear portion 6161Rc. The stepped gear support shaft 6126f of the drive side bearing 6126 is inserted into the support hole 6161Ra. The large diameter gear portion 6161Rb is disposed downstream of the small diameter gear portion Re in the Y2 direction and is formed integrally with the small diameter gear portion
6161Rc. A plurality of teeth are formed on the outer circumferential surfaces of
the large diameter gear portion 6161Rb and the small diameter gear portion
6161Rc and are arranged in the circumferential direction around the rotation axis
M8. In this embodiment, the gear ratio between the large diameter gear portion
6161Rb and the small diameter gear portion 6161Re is 2:1.
[1447] The large diameter gear portion 6161Rb meshes with a rack gear
6162Rf of the movable member 6162R, and the small diameter gear portion
6161Rc meshes with a rack gear 6152Rf of the pressed member 6152R. Afirst
restricting rib 6161Rd is formed on the side of the large diameter gear portion
6161Rb in the Y1 direction, and a second restricting rib 6161Re is formed on the
side of the large diameter gear portion 6161Rb in the Y2 direction. Thefirst
restricting rib 6161Rd restricts the movement of the pressed member 6152R in
the Y2 direction by abutment against the pressed member 6152R. The second
restricting rib 6161Re regulates the movement of the stepped gear 6161R in the
Y2 direction by abutting against the development covering member 6128.
[Assembly of Separation/Contact Mechanism 6150R]
[1448] Next, referring to part (a) of Figure 304 to part (b) of Figure 310, the
assembly of the separating/contacting mechanism 6150R will be described. Part
(a) of Figure 304 is a view illustrating a method of assembling the movable
member 6162R, the compression spring 6153R, and the holding member 6151R,
and part (b) of Figure 304 is a perspective view illustrating the movable member
6162R, the compression spring 6153R, and the holding member 6151R in an
assembled state. Part (a) of Figure 305 is a perspective view illustrating how the assembled movable member 6162R, compression spring 6153R and holding member 6151R are assembled to the development cover member 6128, and part
(b) of Figure 305 is a side view illustrating how the assembled movable member
6162R, compression spring 6153R and holding member 6151R are assembled to
the development cover member 6128. Part (a) of Figure 306 and part (b) of
Figure 306 are perspective views showing a state in which the movable member
6162R, the compression spring 6153R, and the holding member 6151R are
assembled to the development covering member 6128.
[1449] Part (a) of Figure 307 and part (b) of Figure 307 are perspective views
showing how the pressed member 6152R, the stepped gear 6161R, and the
compression spring 6163R are assembled to the drive side bearing 6126. Figure
308 is a perspective view illustrating the state in which the pressed member
6152R, the stepped gear 6161R, and the compression spring 6163R have been
assembled to the drive side bearing 6126. Figure309 is an illustration showing
how the drive side bearing 6126 and the development covering member 6128 are
assembled together. Part (a) of Figure 310 is a front view illustrating the
separation/contact mechanism 6150R, and part (b) of Figure 310 is a sectional
view taken along a line 310B-310B in part (a) of Figure 310.
[1450] As shown in part (a) of Figure 304 and part (b) of Figure 304, the
movable member 6162R and the holding member 6151R are assembled as
follows. That is, after the holding member 615IR is inserted into the movable
member 6162R in the XB direction, they are assembled so that the locking
portion 6162Rc of the movable member 6162R abuts against the locked portion
6151Re of the holding member 6151R, and the abutment surface 6162Rd of the
movable member 6162R abuts against the abutted surface 6151Rf of the holding
member6151R. At this time, the locking portion 6162Rc is placed downstream,
in the Y2 direction, of the locked portion 6151Re, and the abutment surface
6162Rd is placed downstream, in the ZB direction, of the abutted surface 6151Rf.
[1451] The compression spring 6153R is fitted around a boss 6162Rh of the
movable member 6162R and a boss 6151Rk of the holding member 6151R, and
is compressed between the spring seats 6162Rg and 6151Rj. Atthistime,the
holding member 6151R is urged in the ZB direction relative to the movable
member 6162R by the urging force of the compression spring 6153R. By this,
the holding member 6151R is restricted in movement in the ZB direction relative
to the movable member 6162R with the abutted surface 6151Rf being pressed
against the abutment surface 6162Rd of the movable member 6162R. When the
holding member 6151R is moved in the -ZB direction against the urging force of
the compression spring 6153R by an external force, the locked portion 6151Re
abuts against the rise restriction surface 6162Re of the movable member 6162R,
thereby restricting the movement of the holding member 6151R in the -ZB
direction. It can be said that the compression spring 6153R as a holding
member urging portion urges the holding member 6151R against the movable
member 6162R so that the contact force receiving surface 6151Rg faces in a
direction away from the rotation axis M2 of the developing roller 106 in the ZB
direction.
[1452] As shown in parts (a) and (b) of Figures 305 and 306, the movable
member 6162R, the compression spring 6153R and the holding member 6151R,
which are assembled in advance, are inserted into the development covering
member 6128 in the -ZB direction. The movable member 6162R, the
compression spring 6153R and the holding member 6151R are inserted until the
holding member 6151R abuts against the abutment surface 6128e of the
development cover member 6128.
[1453] At this time, the supported surfaces 6162Ra, 6162Rb of the movable
member 6162R are supported by the movable member supporting surfaces 6128a,
6128b of the development covering member 6128, and the guided portion
6151Rd of the holding member 6151R is supported by the holding member
supporting surfaces 6128c, 6128d of the development covering member 6128.
By this, the movable member 6162R and the holding member 6151R are movable
in the ZB direction. As shown in part (b) of Figure 305 and part (a) of Figure
306 and part (b) of Figure 306, the movable member 6162R is disposed
downstream in the Y1 direction with respect to the development covering
member 6128, and the holding portion 6151Rb of the holding member 6151R is
disposed downstream in the Y2 direction.
[1454] As shown in part (a) of Figure 307, part (b) of Figure 307 and Figure
308, the pressed member 6152R is assembled to the drive side bearing 6126 in
the Y1 direction. At this time, the supported surfaces 6152Ra, 6152Rb of the
pressed member 6152R are supported by the support surfaces 6126a, 6126b of
the drive side bearing 6126 so as to be movable in the ZB direction. A
compression spring 6163R is disposed between the spring seat 6152Re of the pressed member 6152R and the spring seat 6126e of the drive side bearing 6126
in a compressed state. The pressed member 6152R is urged in the -ZB direction
against the drive side bearing 6126 by the urging force of the compression spring
6163R. By this, the pressed member 6152R is positioned in a state in which the
abutted surfaces 6152Rc, 6152Rd is abutted by the abutment surfaces 6126c, 6126d of the drive side bearing 6126.
[1455] For the stepped gear 6161R, the stepped gear support shaft 6126f of the drive side bearing 6126 is inserted into a support hole 6161Ra, so that it is
rotatable about a rotation axis M8. The small diameter gear portion 6161Rc of
the stepped gear 6161R meshes with the rack gear 6152Rf of the pressed member
6152R.
[1456] As shown in Figure 309, the development covering member 6128 is provided with the support shafts 6128m and 6128n projecting in the Y1 direction.
In addition, the drive side bearing 6126 is provided with through holes 6126m
and 6126n. A developer container 125 is provided downstream of the drive side
bearing 6126 in the Y1 direction, and the developer container 125 is provided
with support holes 125m and 125n which are disposed at positions corresponding
to the through holes 6126m and 6126n.
[1457] The development covering member 6128 to which the movable
member 6162R, the compression spring 6153R and the holding member 6151R
have been assembled is assembled in the Y1 direction toward the drive side
bearing 6126 to which the pressed member 6152R, the stepped gear 6161R and
the compression spring 6163R have been assembled. At this time, the abutted
surfaces 6152Rc, 6152Rd of the pressed member 6152R are in contact with the
abutment surfaces 6126c, 6126d of the drive side bearing 6126. In addition, the
holding member 6151R is in contact with the abutment surface 6128e of the
development covering member 6128. Therefore, the large diameter gear portion
6161Rb of the stepped gear 6161R is in meshing engagement with the rack gear
6162Rf of the movable member 6162R at a predetermined phase.
[1458] The support shafts 6128m and 6128n of the development cover
member 6128 are inserted into the support holes 125m and 125n of the developer
container 125 in a state that they penetrate the through holes 6126m and 6126n of
the drive side bearing 6126. As shown in Figure 310, the development covering
member 6128 is fixed to the developer container 125 by way of the drive side
bearing 6126 by means of a fixing screw 6145 and an adhesive (not shown).
The method of fixing the development cover member 6128 is not limited to this
example, and may be a connecting method such as welding by heat or pouring
and hardening a resin.
[1459] As shown in part (b) of Figure 310, when the separation/contact mechanism 6150R is assembled, the stepped gear 6161R, the pressed member
6152R, the movable member 6162R, and the holding member 6151R are
positioned in place, that is, they are restricted in movement, in the Y1 and Y2
directions as follows. In addition, in part (b) of Figure 310, the developing drive
input gear 132 and the developing roller gear 131 (see Figure 15) are not shown.
[1460] An end surface 6161Rf of the stepped gear 6161R is restricted in
movement in the Y1 direction by the development cover member 6128 of the
drive side bearing 6126, and the second restricting rib 6161Re is restricted in
movement in the Y2 direction by the restricting surface 6128f of the development
covering member 6128. The pressed member 6152R is restricted in movement
in the Y1 direction by the development cover member 6128 of the drive side
bearing 6126, and is restricted in movement in the Y2 direction by the first
restricting rib 6161Rd of the stepped gear 6161R.
[1461] The movement of the movable member 6162R is restricted in the Y1
direction by the second restriction surfaces 6126h and 6126i of the drive side
bearing 6126, and is restricted in the Y2 direction by the restricting surface 6128f
of the development covering member 6128. The holding portion 6151Rb of the
holding member 6151R is restricted in movement in the Y1 direction by the
development covering member 628, and the locked portion 6151Re is restricted
in movement in the Y2 direction by the locking portion 6162Rc of the movable
member 6162R.
[Movements of movable member 6162R and holding member 6151R in ZB
direction]
[1462] Next, referring to part (a) of Figure 311 and part (b) of Figure 311, the
operation of the movable member 6162R and the holding member 6151R in the
ZB direction (and in -ZB direction) will be described. Part (a) of Figure 311 is a
cross-sectional view illustrating a state before the pressed member 6152R is pressed by the cartridge pressing mechanism 191 (see part (a) of Figure 316).
Part (b) of Figure 311 is a cross-sectional view illustrating a state in which the
pressed member 6152R is pressed by the cartridge pressing mechanism 191 (see
part (a) of Figure 316).
[1463] As shown in part (a) of Figure 311, before the pressed member 6152R
is pressed by the cartridge pressing mechanism 191, the movable member 6162R
is placed at the standby position, and the holding member 6151R is placed at the
standby position. At this time, the developing unit 6109 is in the contact
position.
[1464] When the holding member 6151R is located at the standby position, the
abutment surface 6162Rd of the movable member 6162R abuts against the
abutted surface 6151Rf of the holding member 6151R. That is, the distance
between the abutment surface 6162Rd and the abutted surface 6151Rf is distance
QO=O.
[1465] When the cartridge pressing mechanism 191 presses the pressed
surface 6152Rg of the pressed member 6152R, a force F10 acts on the pressed
surface 6152Rg in the ZB direction. Then, the pressed member 6152R moves in
the ZB direction against the urging force Fl1 of the compression spring 6163R.
Since the rack gear 6152Rf of the pressed member 6152R and the small diameter
gear portion 6161Rc of the stepped gear 6161R are in meshing engagement with
each other, the stepped gear 6161R rotates in the V10 direction, when the rack
gear 6152Rf moves in the ZB direction.
[1466] In addition, since the large diameter gear portion 6161Rb of the
stepped gear 6161R is in meshing engagement with the rack gear 6162Rf of the
movable member 6162R, the movable member 6162R is moved in the ZB
direction, by rotation of the stepped gear 6161R in the V1O direction. Bythis,
the movable member 6162R is moved from the standby position to the projecting position as shown in part (b) of Figure 311.
[1467] In this embodiment, the gear ratio between the large diameter gear
portion 6161Rb and the small diameter gear portion 6161Rc of the stepped gear
6161R is 2:1, and therefore, the movement amount of the movable member
6162R (movement amount D61 in part (b) of Figure 299) is twice the movement
amount of the pressed member 6152R (movement amount D60 in part (b) of
Figure299). The gear ratio between the large diameter gear portion 6161Rb and
the small diameter gear portion 6161Rc of the stepped gear 6161R is not limited
to this example and may be selected appropriately. Moreover, the stepped gear
6161R may be omitted, and the pressed member 6152R and the movable member
6162R may be structured so as to move by the same amount.
[1468] The abutted surface 6151Rf of the holding member 6151R is urged in
the ZB direction by the urging force F20 of the compression spring 6153R, and
therefore, when the movable member 6162R moves in the ZB direction from the
standby position to the projecting position, the holding member 6151R also
moves in the ZB direction. At this time, the holding member 6151R moves
from the standby position to the upper position as shown in part (b) of Figure 311.
In the state that the holding member 6151R is placed at the upper position, the
abutted surface 6151Rf of the holding member 6151R is spaced from the
abutment surface 6162Rd of the movable member 6162R. That is, the distance
between the abutment surface 6162Rd and the abutted surface 6151Rf is a
distance QI which is greater than the distance QO. The mechanism by which
the abutted surface 6151Rf and the abutment surface 6162Rd are spaced from
each other will be described hereinafter.
[1469] When the cartridge pressing mechanism 191 does not presses the
pressed member 6152R against the pressed surface 6152Rg and the force F10
acting on the pressed surface 6152Rg disappears, as shown in part (b) of Figure
311, the pressed member 6152R is moved in the - ZB direction by the urging
force F13 of the compression spring 6163R.
[1470] The rack gear 6152Rf of the pressed member 6152R and the small
diameter gear portion 6161Rc of the stepped gear 6161R are in meshing
engagement with each other, and therefore, when the rack gear 6152Rf moves in
the -ZB direction, the stepped gear 6161R rotates in the VI Idirection opposite to
the V10 direction.
[1471] In addition, the large diameter gear portion 6161Rb of the stepped gear
6161R is in meshing engagement with the rack gear 6162Rf of the movable
member 6162R, and therefore, when the stepped gear 6161R rotates in the VII
direction, the movable member 6162R moves in the -ZB direction. By this, the
movable member 6162R moves from the projecting position to the standby
position, as shown in part (a) of Figure 311. Further, with the movement of the
movable member 6162R in the -ZB direction, the holding member 6151R also
moves in the -ZB direction. At this time, the holding member 6151R moves
from the upper position to the standby position.
[Drive side cartridge cover member]
[1472] Figure 312 is a perspective view illustrating the assembling of the
drum unit 108 and the developing unit 6109. Part (a) of Figure 313 is a
perspective view illustrating the drive side cartridge cover member 6116, and part
(b) of Figure 313 is a view illustrating the separating/contacting mechanism
6150R.
[1473] As shown in Figure 312, the drum unit 108 and the developing unit
6109 are connected by a drive side cartridge cover member 6116 and a non-drive
side cartridge cover member 6117, similarly to Embodiment 1. The outer
diameter portion of the cylindrical portion 6128b of the development cover
member 6128 fits to the developing unit support hole 6116a of the drive side cartridge cover member 6116. By this, the developing unit 6109 is supported so as to be swingable about the swing axis K relative to the drum unit 108. The drive side cartridge cover member 6116 is fixed to the frame (first frame) of the drum unit 108 by a fixing screw or screws 6145. The non-drive side cartridge cover member 6117 is also fixed to the frame (first frame) of the drum unit 108 in the same manner.
[1474] The drive side cartridge cover member 6116 and the non-drive side
cartridge cover member 6117 may be integral with the drum unit 108. In such a
case, the developing unit 6109 may be structured so as to be assembled by
deforming a part of the drive side cartridge cover member 6116 and the non-drive
side cartridge cover member 6117.
[1475] As shown in part (a) of Figure 313, the drive side cartridge cover
member 6116 has a locking surface 6116p and a contacted surface 6116q. The
locking surface 6116p locks the contact portion 6151Rc of the holding member
6151R in the ZB direction. The contacted surface 6116q is formed parallel to
the ZB direction and faces in the XB direction. In addition, the contacted
surface 6116q is capable of contacting the contact portion 6151Rc of the holding
member6151R. The contacted surface 6116q does not necessarily have to be
formed parallel to the ZB direction. For example, it may be a surface which
slopes in the ZB direction as it goes in the -ZB direction. This is to suppress
friction between the contact portion 6151Rc and the contacted surface 6116q at
the time when the contact portion 6151Rc of the holding member 6151R slides
on the contacted surface 6116q, thus reducing wearing and deformation of the
contact portion 6151Rc and the contacted surface 6116q. Inaddition,the
contacted surface 6116q may be structured to have an inclination which slopes in
the -XB direction as it goes in the -ZB direction, as long as a certain degree of
frictional force can be produced between the contact portion 6151Rc and the contacted surface 6116q.
[1476] Part (b) of Figure 313 is a view of the drive side cartridge cover member 6116 in which a part is cut out along a partial cross-sectional line CS11.
In Figure 317 to 323, part (a) of Figure 324 and part (b) of Figure 325, a part of
the drive side cartridge cover member 6116 is cut out along the partial cross
sectional line CS11.
[1477] As shown in part (b) of Figure 313, the distance between the photosensitive drum 104 and the developing roller 106 is by a separation amount
P. When the developing unit 6109 is placed at the contact position, the
separation amount P is 0, and when the developing unit 6109 is placed at the
separated position, the separation amount P is a value (distance) P1 that is greater
than 0. The distance between the abutment surface 6162Rd of the movable
member 6162R and the abutted surface 6151Rf of the holding member 6151R is
a separation amount Q. As described in part (a) of Figure 311, when the holding
member 6151R is placed at the standby position, the separation amount Q is
Q0=0. As shown in part (b) of Figure 311, when the holding member 6151R is placed in the upper position, the distance Q is a value (distance) Q Iwhich is
greaterthan0. As shown in Figure 321, when the holding member 6151R is
placed in the upper position, the separation amount Q is Q0=0.
[1478] A holding portion 6151Rb of the holding member 6151R is
sandwiched between the drum unit 108 and the developing unit 6109to maintain
the developing unit 6109 in the separated position, during non-printing operation.
In other words, the holding portion 6151Rb contacts the drive side cartridge
cover member 6116, which is a part of the first frame of the drum unit 108, and
the development cover member 6128, which is a part of the second frame of the
developing unit 6109, thereby restricting the movement of the developing unit
6109 from the separated position to the contact position (developing position).
At this time, the holding portion 6151Rb is placed at the separation holding
position which is the first position for holding the developing unit 6109 at the
separated position.
[Structure of Image Forming Apparatus Main Assembly 170]
[1479] Next, referring to Figure 314 to part (b) of Figure 316, the description
will be made as to the structure of the main assembly of the image forming
apparatus (apparatus main assembly) 170 relating to the operation of the
separation/contact mechanism 6150R. Figure 314 is a side view illustrating the
cartridge pressing mechanism 191, the cartridge tray 171, and the separation
control unit 195R. Part (a) of Figure 315 is an enlarged view illustrating the
separation control unit 195R, and part (b) of Figure 315 is a perspective view
illustrating the separation control unit 195R. Part (a) of Figure 316 and part (b)
of Figure 316 are perspective views showing the cartridge pressing mechanism
191.
[1480] As shown in Figure 314, the process cartridge 6100 is mounted on the
cartridge tray 171 and is then mounted into the image forming apparatus main
assembly 170. A cartridge pressing mechanism 191 is disposed above the
process cartridge 6100 mounted in the image forming apparatus main assembly
170, and the cartridge pressing mechanism 191 is capable of pressing the pressed
member 6152R of the separation/contact mechanism 6150R.
[1481] In addition, a separation control unit 195R is arranged below the
process cartridge 6100, and the separation control unit 195R includes a holder
199 fixed to the image forming apparatus main assembly 170, a control metal
plate 197 supported so as to be movable in the W41 direction and the W42
direction relative to the holder 199, a separation control member 6196R
supported by the holder 199 and movable in the W41 direction and the W42
direction by the control metal plate 197, and an urging spring 198 having a coil spring.
[1482] As shown in part (a) of Figure 315, and as described above, four
separation control members 6196R are provided corresponding to the process
cartridges of respective colors. The separation control member 6196R is
provided rotatably about a rotation center 6196Re, and is urged in the V12
direction by the urging spring 198.
[1483] The separation control member 6196R is formed to have a recessed
portion, providing a space 6196Rd, and has a second force application surface
(retraction force application portion, separating force application portion) 6196Rb,
an opposing surface 6196Rk opposing the second force applying surface 6196Rb,
and a first force application surface (force application portion, contact force
application portion) 6196Ra formed continuously from the opposing surface
6196Rk. The second force applying surface 6196Rb and the opposing surface
6196Rk are connected by way of a connecting portion 6196Rc with each other.
The first force applying surface 6196Ra is the surface on the opposite side to the
connecting portion 6196Rc, with the opposing surface 6196Rk interposed
therebetween.
[1484] As shown in part (b) of Figure 315, a hole 199a is formed in the holder
199, and the hole 199a has an upper restricting surface 199b and a lower
restricting surface 199c below the upper restricting surface 199b. The upper
restricting surface 199b extends parallel to the W41 direction. The lower
restricting surface 199c has a first lower restricting surface 199c1, a second lower
restricting surface 199c2, and an inclined surface 199c3.
[1485] The first lower restricting surface 199c1 and the second lower
restricting surface 199c2 extend parallel to the W41 direction, and the first lower
restricting surface 199c1 is disposed downstream in the W41 direction from the
second lower restricting surface 199c2. The inclined surface 199c3 connects the first lower restricting surface 199c1 and the second lower restricting surface
199c2, and extends upward as goes in the W42 direction. That is, the second
lower restricting surface 199c2 is positioned higher than the first lower restricting
surface 199c1, and the width G12 between the second lower restricting surface
199c2 and the upper restricting surface 199b is narrower than the width GIl
between the first lower restricting surface 199c1 and the upper restricting surface
199b.
[1486] The separation control member 6196R has a support boss 6196Rs
which projects in the Y2 direction and is inserted into the hole 199a and a
projection 6196Rt. The support boss 6196Rs is supported by the upper
restricting surface 199b and the second lower restricting surface 199c2 so as to be
movable in the W41 direction and the W42 direction. The separation control
member 6196R may be supported by the control metal plate 197 instead of the
holder 199, so that movement thereof in the up and down direction is restricted.
[1487] The projection 6196Rt overlaps the upper restricting surface 199b and
the lower restricting surface 199c in the W41 direction. The separation control
member 6196R is restricted from rotating in the V12 direction by the projection
6196Rt abutting against the upper restricting surface 199b, and is restricted from
rotating in the V13 direction opposite to the V12 direction by the projection
6196Rt abutting against the lower restricting surface 199c.
[1488] As shown in part (a) of Figure 316 and part (b) of Figure 316, in interrelation with the front door 11 (see Figure 2) of the image forming apparatus
main assembly 170 changing from the open state to the closed state, the cartridge
pressing mechanism 191 lowers in the direction of arrow ZA, so that the first
force application portion 191a presses the pressed surface 6152Rg of the pressed
member 6152R. By this, as described in part (a) of Figure 311 and part (b) of
Figure 311, the movable member 6162R moves from the standby position to the projecting position, and the holding member 6151R moves from the standby position to the upper position.
[Operation of holding member 6151R by opening and closing front door 11]
[1489] Next, referring to Figures 317 and 318, the operation of the holding
member 6151R caused by opening and closing of the front door 11 will be
described. Figure 317 is an illustration of the holding member 6151R and the
separation control member 6196R when the front door 11 is in the open state.
Figure 318 is an illustration of the holding member 6151R and the separation
control member 6196R when the front door 11 is closed. However, in Figure
318, some parts such as the drum coupling member 143, the drum flange 142,
and the developing roller gear 131 are not shown.
[1490] As shown in Figure 317, when the process cartridge 6100 is mounted
in the image forming apparatus main assembly 170 and the front door 11 is open,
the cartridge pressing mechanism 191 does not press the pressed member 6152R.
At this time, the movable member 6162R is placed at the standby position, and
the holding member 6151R is placed at the standby position. Therefore,the
separation amount Q between the abutment surface 6162Rd of the movable
member 6162R and the abutted surface 6151Rf of the holding member 6151R is
zero.
[1491] In addition, the developing unit 6109 is urged in the V2 direction by a
moment M10 by the urging force of a development pressure spring 134 (see
Figure 34) functioning as an urging portion, and is placed at the contact position.
In other words, the separation amount P between the photosensitive drum 104
and the developing roller 106 is zero. In addition, the separation control
member 6196R is urged in the V12 direction by a moment M20 produced by the
urging force of the urging spring 198. The projection 6196Rt of the separation
control member 6196R abuts against the upper restricting surface 199b, thereby restricting rotation. When the movable member 6162R is placed at the standby position, the contact portion 6151Rc of the holding member 6151R is spaced from the locking surface 6116p of the drive side cartridge cover member 6116.
[1492] When the front door 11 is closed, as shown in Figure 318, the pressed
surface 6152Rg (see part (a) of Figure 316) of the pressed member 6152R is
pressed by the lowering cartridge pressing mechanism 191 to move in the ZB
direction. By this, the movable member 6162R and the holding member 6151R
also move in the ZB direction.
[1493] By the holding member 6151R moving in the ZB direction, the contact
force receiving surface 6151Rg of the holding member 6151R is brought into
contact with the first force applying surface 6196Ra of the separation control
member6196R. The contact force receiving surface 6151Rg presses the first
force applying surface 6196Ra with the urging force F20 of the compression
spring 6153R. By doing so, the separation control member 6196R is rotated in
the V13 direction against a moment M20 produced by the urging force of the
urging spring 198. In this embodiment, the urging force (F20) of the
compression spring 6153R is selected to be greater than the urging force of the
urging spring 198.
[1494] While the holding member 6151R is moving in the ZB direction
together with the movable member 6162R, the contact portion 6151Re abuts
against the locking surface 6116p of the drive side cartridge cover member 6116.
By this, in the process of movement of the movable member 6162R in the ZB
direction, the movement of the holding member 6151R in the ZB direction is
restricted, and the abutment surface 6162Rd of the movable member 6162R
moves away from the abutted surface 6151Rf of the holding member 6151R.
Therefore, the separation amount Q between the abutment surface 6162Rd and
the abutted surface 6151Rf becomes greater than zero. Therefore, the holding member 6151R is placed in the upper position.
[1495] When the contact portion 6151Rc of the holding member 6151R abuts
against the locking surface 6116p, the separation control member 6196R is placed
at the home position shown in Figure 318. When the separation control member
6196R is placed at the home position, the projection 6196Rt of the separation
control member 6196R is spaced apart from the upper restricting surface 199b
and from the lower restricting surface 199c. Also in the state shown in Figure
318, the developing unit 6109 is held in the contact position. In other words, the
locking surface 6116p as the second restricting surface restricts the movement of
the holding portion 6151Rb from the separation release position (second position)
to the separation holding position (first position) in the ZB direction when the
holding portion 6151Rb is positioned at the separation release position (second
position).
[Separating Operation of Developing Unit 6109]
[1496] Next, referring to Figures 319 to 321, a separating operation in which
the developing unit 6109 moves from the contact position (developing position)
to the separated position (retracted position) will be described. Figure319isa
view illustrating the separating operation of the developing unit 6109, in the state
in which the separation control member 6196R is placed at the home position.
Figure 320 is a view illustrating the separating operation of the developing unit
6109, in the state in which the separation control member 6196R has moved in
the W41 direction from the home position. Figure 321 is a view illustrating the
separating operation of the developing unit 6109, in the state in which the
separation control member 6196R has moved in the W42 direction and returned
to the home position again. In Figures 319, 320, and 321, however, some parts
such as the drum coupling member 143, the drum flange 142, the developing
roller gear 131, and so on are not shown.
[1497] Figure 319 shows the same state as Figure 318, with the movable
member 6162R in the projecting position, the holding member 6151R in the
upper position (second operating position), the developing unit 6109 in the
contact position, and the separation control member 6196R in the home position.
As shown in Figure 319, when the separation control member 6196R moves in
the W41 direction from the home position, the separating force receiving surface
6151Rh of the holding member 6151R receives a force F21 from the second force
applying surface 6196Rb of the separation control member 6196R.
[1498] When the holding member 6151R receives the force F21, as shown in
Figure 320, the developing unit 6109 swings in the VI direction against the
moment M1 of the development pressure spring 134 (see Figure 34). Atthis
time, the developing unit 6109 swings to a second separated position which is
further away from the drum unit 108 from the contact position than the separated
position. By this, the contact portion 6151Rc of the holding member 6151R is
released from the engagement with the locking surface 6 1 16 p of the drive side
cartridge cover member 6116. The holding member 615IR is then moved in the
ZB direction by the urging force of the compression spring 6153R, and is placed
at the lower position (first operating position).
[1499] Thereafter, the separation control member 6196R moves in the W42
direction and returns to the home position as shown in Figure 321. The
developing unit 6109 swings in the V2 direction due to a moment M10 produced
by the development pressure spring 134 (see Figure 34). By this, the contact
portion 6151Rc of the holding member 6151R is brought into contact with the
contacted surface 6116q of the drive side cartridge cover member 6116. In
addition, the supported portion 6151Ra of the holding member 6151R abuts
against the holding member support surface 6128d of the development covering
member 6128.
[1500] That is, the holding portion 6151Rb extending from the contact portion
6151Rc of the holding member 6151R to the supported portion 6151Ra is
sandwiched between the contacted surface 6116q of the drive side cartridge cover
member 6116 and the holding member support surface 6128d of the development
cover member 6128. In addition, by the urging force of the development
pressure spring 134 (see Figure 34), the holding portion 6151Rb is sandwiched
with a predetermined force between the contacted surface 6116q and the holding
member support surface 6128d. Therefore, this state can be said to be a state in
which the drive side cartridge cover member 6116 positions and stably holds the
development covering member 6128 in place by way of the holding portion
6151Rb of the holding member 6151R. In other words, the drum unit 108
positions the developing unit 6109 at the separated position by way of the holding
member 6151R and stably holds it. At this time, the holding portion 6151Rb is
placed at a separation holding position which is a first position for holding the
developing unit 6109 at the separated position.
[1501] In the process of the developing unit 6109 being swinging from the
second separated position to the separated position, the contact force receiving
surface 6151Rg of the holding member 6151R placed in the lower position
presses the first force applying surface 6196Ra of the separation control member
6196R. At this time, the urging force of the compression spring 6153R is
selected to be greater than the urging force of the urging spring 198, and therefore,
the holding member 6151R remains in the lower position.
[1502] Then, the separation control member 6196R rotates in the V13
direction against the urging force of the urging spring 198. When the
developing unit 6109 is held at the separated position by the holding portion
6151Rb of the holding member 6151R, the projection 6196Rt of the separation
control member 6196R is in contact with or in close proximity to the first lower restricting surface 199c1.
[Contact Operation of Developing Unit 6109]
[1503] Next, referring to Figures 322 to 324, a contact operation in which the
developing unit 6109 moves from the separated position (retracted position) to
the contact position (developing position) will be described. Figure 322 is a
view illustrating the contact operation of the developing unit 6109, in the state in
which the separation control member 6196R is located at the home position.
Figure 323 is a view illustrating the contact operation of the developing unit 6109,
in the state in which the separation control member 6196R has moved in the W42
direction from the home position. Figure 324 is a view illustrating the contact
operation of the developing unit 6109, in the state in which the separation control
member 6196R has moved in the W41 direction and returned to the home
position again. In Figures 322, 323 and 324, however, some parts such as the
drum coupling member 143, the drum flange 142, and the developing roller gear
131 are not shown.
[1504] Figure 322 shows the same state as Figure 321, with the movable
member 6162R in the projecting position, the holding member 6151R in the
lower position (first operating position), the developing unit 6109 in the separated
position, and the separation control member 6196R in the home position. As
shown in Figure 322, when the separation control member 6196R moves in the
W42 direction from the home position, the contact force receiving surface
6151Rg of the holding member 6151R receives a force F22, a force F23 or a
force F24 from the first force applying surface 6196Ra of the separation control
member 6196R.
[1505] That is, in the process of the holding member 6151R being moving in
the W42 direction from the home position, the contact force receiving surface
6151Rg of the holding member 6151R receives a force F22 from the first force applying surface 6196Ra of the separation control member 6196R, as long as the projection 6196Rt is in sliding contact with the first lower restricting surface
199c1. In addition, while the projection 6196Rt is in sliding contact with the
second lower restricting surface 199c2 after riding over the inclined surface
199c3, the contact force receiving surface 6151Rg of the holding member 6151R
receives the force F23 from the first force applying surface 6196Ra of the
separation control member 6196R. Further, while the projection 6196Rt is
riding the inclined surface 199c3, the contact force receiving surface 6151Rg of
the holding member 6151R receives the force F24 from the first force applying
surface 6196Ra of the separation control member 6196R.
[1506] The separation control member 6196R rotates in the V12 direction as a
result of the projection 6196Rt riding on the inclined surface 199c3. By the
separation control member 6196R rotating in the V12 direction, the first force
applying surface 6196Ra significantly presses up the contact force receiving
surface 6151Rg, and therefore, the force and amount of force F24 pressing up the
holding member 6151R in the -ZB direction is greater than the forces F22 and
F23. In addition, when the projection 6196Rt is in contact with the first lower
restricting surface 199c1, the second lower restricting surface 199c2, or the
inclined surface 199c3, the rotation of the separation control member 6196R in
the V13 direction is restricted, so that even if the urging force of the urging spring
198 is smaller than the urging force of the compression spring 6153R, the first
force applying surface 6196Ra can push up the contact force receiving surface
6151Rg. Therefore, the holding member 615IR moves in the -ZB direction
against the urging force F20 of the compression spring 6153R. In this manner,
by lifting the holding member 6151R in the -ZB direction by forces F22, F23 and
F24, the holding member 6151R can be reliably moved to the upper position (see
Figure 323).
[1507] As shown in Figure 323, the holding member 6151R moves in the -ZB
direction to be positioned at a raised position (second operating position). By
this, the contact portion 6151Rc of the holding member 6151R is disengaged
from the contacted surface 6116q of the drive side cartridge cover member 6116.
Then, the developing unit 6109 is swung in the V2 direction by the moment M10
produced by the development pressure spring 134 (see Figure 34) and reaches the
contact position. At this time, the contact portion 6151Rc of the holding
member 615IR is locked by the locking surface 6116p. The holding member
6151R is locked with a predetermined pressure on the locking surface 6116p by
the urging force of the compression spring 6153R to be maintained at the upper
position.
[1508] Thereafter, the separation control member 6196R moves in the W41
direction and returns to the home position as shown in Figure 324. The
separation control member 6196R is urged in the V12 direction by a moment
M20 produced by an urging spring. Therefore, in the process of the separation
control member 6196R being moving in the W41 direction, the first force
applying surface 6196Ra of the separation control member 6196R moves along
the contact force receiving surface 6151Rg of the holding member 6151R. In
the state that the separation control member 6196R has returned to the home
position, the movable member 6162R is at the projecting position, the holding
member 6151R is at the upper position, and the developing unit 6109 is at the
contact position. The holding portion 6151Rb is placed at a separation release
position, which is a second position for holding the developing unit 6109 at the
contact position (developing position). In other words, when the holding
portion 6151Rb is in the separation release position, it allows the developing unit
6109 to move from the separated position to the contact position (developing
position). In this state, the printing operation is carried out.
[1509] In this manner, when the movable member 6162R is placed at the
standby position, the holding member 6151R is placed at the standby position
shown in Figure. In addition, when the movable member 6162R is in the
projecting position, the holding member 6151R can take a lower position (first
operating position) or an upper position (second operating position). When the
holding member 6151R is placed in the lower position (firstoperating position),
the developing unit 6109 is placed in the separated position, and when the
holding member 6151R is placed in the upper position (second operating
position), the developing unit 6109 is placed in the contact position.
[1510] In other words, the holding member 6151R, which includes the contact
force receiving surface 6151Rg as a contact force receiving portion, is capable of
taking a standby position, a lower position (first operating position), and an upper
position (second operating position) by moving in the ZB direction, which is a
predetermined direction, relative to the developing unit 6109. The lower
position (first operating position) and the upper position (second operating
position) are positions different from each other, and are positions more outward
of the developing unit 6109 than that of the standby position. In addition, it can
be said that, when the holding member 6151R is placed at the standby position,
the lower position (first operating position), and the upper position (second
operating position) the contact force receiving surface 6151Rg of the holding
member 6151R is also placed at the standby position, the lower position (first
operating position), and the upper position (second operating position),
respectively.
[1511] Then, from a state in which the developing unit 6109 is in the separated
position, the holding portion 6151Rb is in the separation holding position (first
position), and the contact force receiving surface 6151Rg is in a lower position
(first operating position), the contact force receiving surface 6151Rg receives a contact force from the separation control member 6196R to move in the ZB direction (predetermined direction) to an upper position (second operating position), thereby moving from the separation holding position (first position) to the separation release position (second position). Here, the predetermined direction includes the ZB direction and the -ZB direction.
[1512] The above-mentioned separating operation of the developing unit 6109
is executed as an initial operation, when the process cartridge 6100 is mounted in
the image forming apparatus main assembly 170 and then the front door 11 is
closed, for example. By this, the developing roller 106 of the developing unit
6109 can be separated from the photosensitive drum 104, thereby extending the
lifetimes of the developing roller 106 and the photosensitive drum 104 and
suppressing image defects.
[1513] Then, when a command to start printing is outputted to the image
forming apparatus M after the separating operation of the developing unit 6109 is
performed as an initial operation, for example, the contact operation of the
developing unit 6109 is executed before starting printing operation. Then,
printing is started with the developing unit 6109 positioned at the contact position
(the state shown in Figure 324).
[1514] After printing is completed, the developing unit 6109 is separated.
When the developing unit 6109 is in the separated position (the state shown in
Figure 321), the image forming apparatus M is ina standby state. Whenthe
image forming apparatus M is in a standby state and a command to start printing
is outputted to the image forming apparatus M, the contact operation of the
developing unit 6109 is executed as described above.
[Restriction of movement of holding member 6151R in -ZB direction]
[1515] Next, referring to part (a) of Figure 325 to part (b) of Figure 326, a structure for restricting movement of the holding member 6151R in the -ZB direction will be described. Part (a) of Figure 325 is an illustration of the force acting on the separating force receiving surface 6151Rh of the holding member
6151R during the separating operation of the developing unit 6109, and part (b)
of Figure 325 is an illustration of the position of the holding member 6151R in
the state of part (a) of Figure 325. Part (a) of Figure 326 is an illustration of the
state in which the holding member 6151R abuts against the rise restricting surface
6162Re during the separating operation of the developing unit 6109, and part (b)
of Figure 326 is an illustration of the position of the holding member 6151R in
the state of part (a) of Figure 326. In part (a) of Figure 325 and part (a) of
Figure 326, however, some portions such as the drum coupling member 143, the
drum flange 142, and the developing roller gear 131 are not shown.
[1516] As shown in part (a) of Figure 325, when the developing unit 6109
carries out a separating operation, the separation control member 6196R moves in
the W41 direction, and the second force applying surface 6196Rb of the
separation control member 6196R applies a force F21 to the separating force
receiving surface 6151Rh of the holding member 6151R. TheforceF21
includes a -ZB direction component force F21Zb. In addition, when the
moment M10 produced by the urging force of the development pressure spring
134 (see Figure 34) is great, the force F21 is also great. Then, the force F21Zb
may be greater than the urging force F20 of the compression spring 6153R.
[1517] When the force F21Zb is greater than the urging force F20, the second
force applying surface 6196Rb of the separation control member 6196R pushes
up the holding member 6151R in the -ZB direction against the urging force F20.
In the case in which the separation control member 6196R moves in the W41
direction, if the holding member 6151R moves significantly in the -ZB direction
from the upper position, the engagement between the second force applying
surface 6196Rb and the separating force receiving surface 6151Rh is broken, and the separation contact operations of the developing unit 6109 will not be able to be performed properly.
[1518] Therefore, in this embodiment, as shown in part (b) of Figure 325, a
rise restriction surface 6162Re is formed as a first restriction surface on the
movable member 6162R, and the movement of the holding member 6151R in the
-ZB direction is restricted by abutment of the locked portion 6151Re of the
holding member 615IR against the rise restriction surface 6162Re. Inother
words, when the separating force receiving surface 6151Rh receives a separating
force from the separation control member 6196R, the rising control surface
6162Re restricts the movement of the holding portion 6151Rb in the direction
opposite to the direction which is from the separation release position (second
position) to the separation holding position (first position) in the ZB direction.
[1519] Therefore, as shown in part (a) of Figure 326 and part (b) of Figure 326,
even if the second force applying surface 6196Rb of the separation control
member 6196R pushes the holding member 6151R up in the -ZB direction, the
locked portion 6151Re of the holding member 6151R abuts against the rise
restriction surface 6162Re. The structure is such that even in the state that the
locked portion 6151Re abuts against the rise restriction surface 6162Re, the
engagement between the second force applying surface 6196Rb and the
separating force receiving surface 6151Rh is maintained. With such a structure,
when the separation control member 6196R moves in the W41 direction, the
engagement between the second force applying surface 6196Rb and the
separating force receiving surface 6151Rh can be maintained, and the separating
operation and the contact operation of the developing unit 6109 can be performed
appropriately.
[1520] Although the above description has been made about the drive side, the
separation/contact mechanism 6150L is also arranged on the non-drive side. As a result, the same operation can be performed on the non-drive side as well. By performing separation and contact operations on both the drive side and the non drive side, the developing unit 6109 can be swung about the swing axis K reliably and stably.
[1521] According to the structure of this embodiment described above, the
same effects as those of Embodiment 1 and 9 can be provided. In addition, in
this embodiment, the movement of the holding member 6151R only in the ZB
direction (and the -ZB direction) is enough to enable the developing unit 6109 to
be switched between the contact position and the separation position, so that the
space required to place the holding member 6151R can be reduced, and the
process cartridge 6100 to be downsized.
[1522] In addition, in this embodiment, the holding portion 6151Rb and the
free end portion 6151Rm are integrally provided on the holding member 6151R,
but this is not inevitable in this invention. For example, the structure may be
such that the holding portion 6151Rb is provided separately from the free end
portion 6151Rm, and the holding portion 6151Rb is movable between a first
position (separation holding position) and a second position (separation release
position) in interrelation with the free end portion 6151Rm moved by the
separation control member 6196R. In addition, in this embodiment, the holding
member 6151R is supported by the development cover member 6128 of the
developing unit 6109, but the present invention is not limited to such an example.
For example, the holding member 6151R may be movably supported by the drum
unit 108, or may be supported by a movable member 6152R.
[1523] Moreover, Embodiment 32 may be appropriately combined with one or
more of the above-described Embodiments 1 to 31.
<Embodiment 33>
[1524] Next, referring to part (a) of Figure 327 to Figure 338, Embodiment 33 will be described. In this embodiment, the structure and operation different from those of the previously described embodiment 32 will be described, and the same reference numerals will be assigned for the members having similar structures and functions, and the description thereof will be omitted.
[1525] More specifically, the separation/contact mechanism 7150R of this embodiment 33 (see part (a) of Figure 329) has a drive side bearing 6126,
compression springs 6153R, 6163R, a pressed member 6152R, a stepped gear
6161R, a movable member 6162R, and a development cover member 6128,
which are similar to those of the embodiment 32. On the other hand, in
Embodiment 33, instead of the holding member 6151R and the drive side
cartridge cover member 6116 of Embodiment 32, a holding member 7151R and a
drive side cartridge cover member 7116 are provided. In addition, while the
developing unit 6109 in Embodiment 32 is urged toward the contact position by
the urging force of the development pressure spring 134, the developing unit
7109 in Embodiment 33 is urged toward the separated position by the urging force of a development separation spring (not shown).
[Structure of separation/contact mechanism 7150R]
[1526] Next, referring to part (a) of Figure 327 and part (b) of Figure 327, the description will be made as to a holding member 7151R and a drive side cartridge
cover member 7116, which include differences between the separation/contact
mechanism 7150R of this embodiment and the separation/contact mechanism
6150R of Embodiment 32. Part (a) of Figure 327 is a perspective view
illustrating the holding member 7151R, and part (b) of Figure 327 is a front view
illustrating the drive side cartridge cover member 7116.
[1527] As shown in part (a) of Figure 327, the holding member 7151R
includes a guided portion 7151Rd extending in the ZB direction, a holding
portion 7151Rb extending in the -XB direction from the upstream end of the guided portion 7151Rd in the ZB direction, and a free end portion 7151Rm provided at the downstream end of the holding member 7151R in the ZB direction. In addition, the guided portion 7151Rd, the locked portion 7151Re, and the abutted surface 7151Rf of the holding member 7151R have the same structure and function as the guided portion 6151Rd, the locked portion 6151Re, and the abutted surface 6151Rf of the holding member 6151R of Embodiment 32, respectively, and therefore, description thereof will be omitted.
[1528] A supported portion 7151Ra is provided at the downstream end, in the
-XB direction, of the holding portion 7151Rb. On the other hand, a contact
portion 7151Re and an inclined surface 7151Rr are formed at the downstream
end, in the XB direction, of the holding portion 7151Rb. The contact portion
7151Re is formed continuous with the inclined surface 7151Rr, and is disposed
downstream of the inclined surface 7151Rr in the XB direction and downstream
of the inclined surface 7151Rr in the -ZB direction. The inclined surface
7151Rr is slanted downstream in the XB direction as goes in the -ZB direction.
[1529] The free end portion 715IRm as a projecting portion can project
beyond the first frame of the drum unit 108 and the second frame of the
developing unit 7109 at least in a direction away from the rotation axis of the
developing roller 106. The free end 715IRm is formed with a contact force
receiving surface (contact force receiving portion) 7151Rg, a separating force
receiving surface 7151Rh, and a lower surface 7151Rs. Thecontactforce
receiving surface 7151Rg and the separating force receiving surface 7151Rh are
provided at the downstream end, in the ZB direction, of the free end portion
7151Rm, and are inclined surfaces inclined with respect to the ZB direction and
the XB direction, respectively. More specifically, the contact force receiving
surface 7151Rg is an inclined surface which is slanted downstream in the XB
direction as goes in the ZB direction. In other words, as viewed along the rotation axis M1 of the photosensitive drum 104, the contact force receiving surface 7151Rg is inclined so as to approach the rotation axis M1 in the ZB direction as goes approaching the rotation axis M1 in the XB direction which is a direction perpendicular to the ZB direction.
[1530] The separating force receiving surface 7151Rh is a slope which is
slanted in the -XB direction as it goes in the -ZB direction. In other words, as
viewed along the rotation axis M1 of the photosensitive drum 104, the separating
force receiving surface 7151Rh is inclined so as to approach the rotation axis M1
in the ZB direction as goes approaching the rotation axis M1 in the XB direction
which is a direction perpendicular to the ZB direction. The lower surface
7151Rs is disposed downstream in the XB direction beyond the contact force
receiving surface 7151Rg and the separating force receiving surface 7151Rh, and
faces in the ZB direction.
[1531] As shown in part (b) of Figure 327, the drive side cartridge cover
member 7116 includes a main body portion 7116m and a development urging
portion 7116s which can apply a force to the developing unit 7109 to swing it
toward the contact position by pressing the holding portion 7151Rb. The
development urging portion 7116s extends in the ZB direction from the main
body portion 7116m and has an elastically deformable elastic portion 7116n, and
a locking surface 7 1 1 6p and a contacted surface 7116q provided at the free end of
the elastic portion 7116n. The elastic portion 7116n is formed of a leaf spring,
for example, and may be formed as a separate member from the main body
portion 7116m, or may be formed integrally with the main body portion 7116m.
[1532] The contacted surface 7116q is an inclined surface which is slanted in
the XB direction as it goes the -ZB direction, and generally faces in the -XB
direction. The locking surface 7116p as a second regulating surface is formed
continuously with the contacted surface 7116q, and is disposed downstream of the contacted surface 7116q in the -ZB direction. The locking surface 7 1 16 p includes a surface which is parallel to the -XB direction or which faces in the -ZB direction as it goes in the -XB direction.
[Movement of movable member 6162R and holding member 7151R in ZB
direction]
[1533] Next, referring to Figure 328 and part (a) of Figure 329 and part (b) of
Figure 329, the operation of the movable member 6162R and the holding member
715IR in the ZB direction (and -ZB direction) will be described. Figure328isa
side view illustrating a state before the pressed member 6152R is pressed by the
cartridge pressing mechanism 191 (see part (a) of Figure 316). Part (a) of
Figure 329 is a sectional view illustrating a state in which the pressed member
6152R is pressed by the cartridge pressing mechanism 191 (see part (a) of Figure
316). Part (b) of Figure 329 is an enlarged view illustrating the neighborhood of
the locking surface 7116p. In Figure 328 and part (a) of Figure 329, some parts
such as the drum coupling member 143, the drum flange 142, and the developing
roller gear 131 are not shown.
[1534] As shown in Figure 328, before the pressed member 6152R is pressed
by the cartridge pressing mechanism 191, the movable member 6162R is placed
at the standby position, and the holding member 7151R is placed at the standby
position. At this time, the developing unit 7109 is urged in the VI direction by a
moment M30 produced by a development separation spring (not shown). By
this, the distance between the photosensitive drum 104 and the developing roller
106 is separation amount P2, and the developing unit 7109 is placed at the
separated position.
[1535] When the holding member 7151R is placed at the standby position, the
abutment surface 6162Rd of the movable member 6162R abuts against the
abutted surface 7151Rf of the holding member 7151R. That is, the distance between the abutment surface 6162Rd and the abutted surface 7151Rf is distance
QO=O.
[1536] As shown in part (a) of Figure 329, when the cartridge pressing mechanism 191 (see part (a) of Figure 316) presses the pressed surface 6152Rg
of the pressed member 6152R, the movement of the pressed member 6152R is
accelerated by the stepped gear 6161R (see part (b) of Figure 311) and
transmitted to the movable member 6162R, so that the movable member 6162R
moves in the ZB direction, as described in Embodiment 32. By doing so, the
movable member 6162R is moved to the projecting position shown in part (a) of
Figure 329.
[1537] In addition, as shown in part (a) of Figure 329 and part (b) of Figure 329, the holding member 7151R moves in the ZB direction together with the
movable member 6162R, but while the movable member 6162R is moving in the
ZB direction toward the projecting position, the holding portion 7151Rb of the
holding member 7151R abuts against the locking surface 7 1 16 p of the drive side cartridge cover member 7116. By doing so, the movement of the holding
member 7151R in the ZB direction is restricted, and the abutment surface
6162Rd of the movable member 6162R moves away from the abutted surface
7151Rf of the holding member 7151R.
[1538] Therefore, with the movable member 6162R placed in the projecting
position, the separation amount Q2 between the abutment surface 6162Rd and the
abutted surface 7151Rf is greater than 0, and the holding member 7151R is
placed in the upper position. At this time, the developing unit 7109 is
maintained in the separated position by a moment M30 produced by the
development separation spring (not shown).
[Structure of Main Assembly 170 of Image Forming Apparatus]
[1539] Next, referring to Figure 330, the structure of the image forming apparatus main assembly (apparatus main assembly) 170 side relating to the operation of the separation/contact mechanism 6150R will be described. In this embodiment, the structure of the image forming apparatus main assembly 170 side is the same as in Embodiments 1 and 32.
[1540] Figure 330 is a front view illustrating the separation control unit 195R.
The separation control member 7196R of the separation control unit 195R in this
embodiment has the same structure as that of Embodiment 32, but the positions
of the first force application surface (force application portion, abutment force
application portion) and the second force application surface (retraction force
application portion, separating force application portion) are slightly different
from those of Embodiment 32. The separation control member 7196R is formed
with a part recessed to form a space 7196Rd, and has afirst force application
surface (force application portion, abutment force application portion) 7196Ra,
an opposing surface 7196Rk opposing the first force applying surface 7196Ra,
and a second force application surface (retraction force application portion,
separating force application portion) 7196Rb formed continuously with the
opposing surface 7196Rk. In addition, the separation control member 7196R
has an upper surface 7196Rs formed adjacent to the first force applying surface
7196Ra. The separation control member 7196R is provided with a projection
7196Rt (see Figure 331) having the same function as that the projection 6196Rt
of the separation control member 6196R of Embodiment 32.
[Operation of holding member 7151R by opening and closing front door 11]
[1541] Next, referring to Figures 331 and 332, the operation of the holding
member 7151R caused by opening and closing the front door 11 will be described.
Figure 331 is an illustration of the holding member 7151R and the separation
control member 7196R at the time when the front door 11 is in the open state.
Figure 332 is an illustration of the holding member 7151R and the separation control member 7196R at the time when the front door 11 is closed. In Figures
331 and 332, some portions such as the drum coupling member 143, the drum
flange 142, and the developing roller gear 131 are not shown.
[1542] As shown in Figure 331, when the process cartridge 7100 as a cartridge
is mounted in the image forming apparatus main assembly 170 and the front door
11 is open, the cartridge pressing mechanism 191 does not press the pressed
member 6152R. At this time, the movable member 6162R is placed at the
standby position, and the holding member 7151R is placed at the standby position.
[1543] In addition, the developing unit 7109 is urged in the VI direction by a
moment M30 by the urging force of the development separation spring (not
shown), and is placed at the separation position. Further, the separation control
member 7196R is urged in the V12 direction by the moment M20 produced by
the urging force of the urging spring 198. The projection 7196Rt of the
separation control member 7196R abuts against the upper restricting surface 199b,
thereby to restrict rotation.
[1544] When the front door 11 is closed, as shown in Figure 332, the pressed
member 6152R (see part (a) of Figure 329) is pressed by the cartridge pressing
mechanism 191 which is lowered, and thereby moves in the ZB direction. By
this, the movable member 6162R and the holding member 7151R also move in
the ZB direction.
[1545] By the movement of the holding member 7151R in the ZB direction, a
lower surface 7151Rs of the holding member 7151R is brought into contact with
an upper surface 7196Rs of the separation control member 7196R. The lower
surface 7151Rs presses the upper surface 7196Rs with the urging force F31 of the
compression spring 6153R. By this, the separation control member 7196R
rotates in the V13 direction against a moment M20 produced by the urging force
of the urging spring 198. In this embodiment, the urging force (F31) of the compression spring 6153R is selected to be greater than the urging force of the urging spring 198. At this time, the separation control member 7196R is placed at the home position. When the separation control member 7196R is placed at the home position, the projection 7196Rt of the separation control member 7196R is spaced apart from the upper restricting surface 199b and the lower restricting surface 199c. Also in the state shown in Figure 332, the developing unit 7109 is held in the separated position.
[1546] In addition, as described in part (a) of Figure 329 and part (b) of Figure
329, in the process of movement of the movable member 6162R in the ZB
direction toward the projecting position, the holding portion 7151Rb of the
holding member 7151R abuts against the locking surface 7 1 16 p of the drive side
cartridge cover member 7116. Therefore, in the state that the movable member
6162R is in the projecting position, the holding member 7151R is in the upper
position.
[Contact Operation of Developing Unit 7109]
[1547] Next, referring to Figures 333 to 335, the contact operation in which
the developing unit 7109 moves from the separated position (retracted position)
to the contact position (developing position) will be described. Figure 333 is an
illustration of the contact operation of the developing unit 7109, in the state in
which the separation control member 7196R is placed at the home position. Part
(a) of Figure 334 is an illustration of the contact operation of the developing unit
7109, and shows the state in which the separation control member 7196R has
moved in the W42 direction from the home position. Part (b) of Figure 334 is
an enlarged view illustrating the neighborhood of the contact portion 7151Re of
the holding member 7151R. Figure 335 is an illustration the contact operation
of the developing unit 7109, showing the state in which the separation control
member 7196R has moved in the W41 direction and has returned to the home position. In Figure 333, part (a) of Figure 334 and Figure 335, some parts such as the drum coupling member 143, the drum flange 142, the developing roller gear 131, and so on are not shown.
[1548] Figure 333 shows the state same as that in Figure 332, with the
movable member 6162R in the projecting position, the holding member 7151R in
the raised position (first operating position), the developing unit 7109 in the
separated position, and the separation control member 7196R in the home
position. In Figure 333, the holding portion 7151Rb of the holding member
7151R is in abutment to the locking surface 7 1 16p of the drive side cartridge
cover member 7116.
[1549] As shown in Figure 333 and part (a) of Figure 334, when the separation
control member 7196R moves in the W42 direction from the home position, the
contact force receiving surface 7151Rg of the holding member 7151R receives a
force F40 from the first force applying surface 7196Ra of the separation control
member 7196R. By doing so, the developing unit 7109 swings in the V2
direction relative to the drive side cartridge cover member 7116 (and the drum
unit 108) against the moment M30 produced by the development separation
spring (not shown). Then, the developing roller 106 of the developing unit 7109
is brought into contact with the photosensitive drum 104, and the developing unit
7109 is placed at the contact position.
[1550] In addition, when the developing unit 7109 swings toward the contact
position, the holding portion 7151Rb of the holding member 7151R moves in a
direction toward the photosensitive drum 104 relative to the locking surface
7116p. By doing so, the engagement between the holding portion 7151Rb and
the locking surface 7 1 16p is broken, and the inclined surface 7151Rr and the
contact portion 7151Re formed on the holding portion 7151Rb is brought into
contact with the contacted surface 7116q of the drive side cartridge cover member 7116, as shown in part (b) of Figure 334.
[1551] At this time, a force F31 in the ZB direction is applied to the holding
member 7151Rby the compression spring 6153R. It canbe said that the
compression spring 6153R as a holding member urging portion urges the holding
member 7151R against the movable member 6162R so that the separating force
receiving surface 7151Rh faces in a direction away from the rotation axis M2 of
the developing roller 106 in the ZB direction. Therefore, the holding member
7151R moves in the ZB direction while the inclined surface 7151Rr and the
contact portion 7151Rc press the contacted surface 7116q with a force F32. The
elastic portion 7116n of the drive side cartridge cover member 7116 is elastically
deformed in the V31 direction by the force F32.
[1552] The movement of the holding member 7151R in the ZB direction stops
by abutting against the abutment surface 6162Rd of the movable member 6162R,
and as a result, the holding member 7151R is positioned at the lower position.
In part (a) of Figure 334 and part (b) of Figure 334, the movable member 6162R
is in the projecting position, the holding member 7151R is in the lower position,
and the developing unit 7109 is in the contact position.
[1553] The contacted surface 7116q of the drive side cartridge cover member
7116 presses the contact portion 7151Rc of the holding member 7151R with a
force F33 by the elastic deformation of the elastic portion 7116n in the V31
direction. In other words, the contacted surface 7116q of the development
urging portion 7116s presses the developing unit 7109 with a force F33 by way of
the contact portion 7151Rc of the holding member 7151R. In other words, the
development urging portion 7116s elastically deforms when the holding portion
7151Rb moves from the separation holding position (first position) to the
separation release position (second position), thereby pressing the holding portion
7151Rb so that the developing unit 7109 moves toward the contact position
(developing position). The developing unit 7109 is urged in the V2 direction by
the force F33 against the moment M30 produced by the development separation
spring, so that the contact position is stably maintained.
[1554] Thereafter, as shown in Figure 335, the separation control member
7196R moves in the W41 direction and returns to the home position. In the
process of the separation control member 7196R being returning to the home
position, the second force applying surface 7196Rb of the separation control
member 7196R abuts against the separating force receiving surface 7151Rh of
the holding member 7151R. Then, the separation control member 7196R rotates
in the V13 direction against the urging force of the urging spring 198 while being
moved in the W41 direction by the second force applying surface 7196Rb being
pressed by the separating force receiving surface 7151Rh. This is because the
urging force of the compression spring 6153R is selected to be greater than the
urging force of the urging spring 198. Therefore, the holding member 715IR
remains in the lower position.
[1555] As shown in Figure 335, in the state that the developing unit 7109 is
held in the contact position and the separation control member 7196R is
positioned in the home position, the projection 7196Rt of the separation control
member 7196R is in contact with or in close proximity to the first lower
restricting surface 199c1. Even in this state, the developing unit 7109 is urged
in the V2 direction against the moment M30 of the development separation spring
by the force F33 received by the contact portion 7151Re from the contacted
surface 7116q, and thus maintaining the contact position stably.
[Separating Operation of Developing Unit 7109]
[1556] Next, referring to Figures 336 to 338, the description will be made as
to the separating operation in which the developing unit 7109 moves from the
contact position (developing position) to the separated position (retracted position). Figure 336 is an illustration the separating operation of the developing unit 7109, in the state in which the separation control member 7196R is placed at the home position. Part (a) of Figure 337 is an enlarged view illustrating the neighborhood of the contacted surface 7116q partway of the separation control member 7196R moving from the home position in the W41 direction. Part (b) of Figure 337 is an illustration of the separating operation of the developing unit 7109, and shows the state in which the separation control member 7196R has moved in the W41 direction from the home position. Figure
338 is an illustration of the separating operation of the developing unit 7109,
showing the state in which the separation control member 7196R has moved in
the W42 direction and returned to the home position again. Here, in Figure 336, part (b) of Figure 337 and Figure 338, some portions such as the drum coupling
member 143, the drum flange 142, the developing roller gear 131, and so on are
not shown.
[1557] Figure 336 shows the state same as that of Figure 335, with the movable member 6162R in the projecting position, the holding member 7151R in
the lower position (second operating position), the developing unit 7109 in the
contact position, and the separation control member 7196R in the home position.
As shown in Figure 336, when the separation control member 7196R moves in
the W41 direction from the home position, the separating force receiving surface
7151Rh of the holding member 7151R abuts against the second force applying
surface 7196Rb of the separation control member 7196R.
[1558] The projection 7196Rt of the separation control member 7196R abuts against the first lower restricting surface 199c1 to restrict the rotation of the
separation control member 7196R in the V13 direction. Therefore,the
separating force receiving surface 7151Rh of the holding member 7151R receives
the force F41 from the second force applying surface 7196Rb of the separation control member 7196R.
[1559] The holding member 7151R is pushed up in the -ZB direction by the
force F41 against the urging force F31 of the compression spring 6153R. The
force for moving the separation control member 7196R in the W41 direction is
sufficiently greater than the urging force F31 of the compression spring 6153R,
and the separation control member 7196R cannot be stopped by the urging force
F31.
[1560] As shown in part (a) of Figure 337, by the holding member 7151R
being pushed up in the -ZB direction, the inclined surface 7151Rr and the contact
portion 7151Re formed on the holding portion 7151Rb is moved in the -ZB
direction while sliding on the contacted surface 7116q of the drive side cartridge
cover member 7116. The holding member 7151R then moves to a position
where the inclined surface 7151Rr is released from contact with the contacted
surface 7116q or to a position beyond the upper position in the -ZB direction.
By doing so, the distance between the abutment surface 6162Rd and the abutted
surface 7151Rf becomes the separation amount Q2, and the holding member
7151R is in the upper position.
[1561] In addition, when the inclined surface 7151Rr and the contacted
surface 7116q are released from contact with each other, the elastic deformation
of the elastic portion 7116n is restored, and the contacted surface 7116q moves in
the V32 direction. As shown in part (b) of Figure 337, when the contact
between the inclined surface 7151Rr and the contacted surface 7116q is broken
and the contacted surface 7116q moves in the V32 direction, the force F33 (see
part (b) of Figure 334) with which the contacted surface 7116q is pressing against
the contact portion 7151Rc is eliminated. Therefore, the developing unit 7109 is
swung in the VI direction by the moment M30 produced by a development
separation spring (not shown) and is placed at the separated position.
[1562] Thereafter, as shown in Figure 338, the separation control member
7196R moves in the W42 direction and returns to the home position. The
separation control member 7196R is urged in the V12 direction by the urging
spring 198, and therefore rotates in the V12 direction while moving in the W42
direction. In the process of transition from the state of part (b) of Figure 337 to
the state of Figure 338, the second force applying surface 7196Rb of the
separation control member 7196R comes into sliding contact with the separating
force receiving surface 7151Rh of the holding member 7151R.
[1563] In addition, while the separation control member 7196R is moving in
the W42 direction, the second force applying surface 7196Rb of the separation
control member 7196R separates from the separating force receiving surface
7151Rh of the holding member 7151R. Then, the upper surface 7196Rs of the
separation control member 7196R is brought into contact with the lower surface
715IRs of the holding member 7151R. In this state, the separation control
member 7196R moves to the home position. When the second force applying
surface 7196Rb separates from the separating force receiving surface 7151Rh, the
force F41 having been described with Figure 336 disappears, and therefore, the
holding member 7151R is urged in the ZB direction by the urging force F31 of
the compression spring 6153R. By this, the holding portion 7151Rb is locked
by the locking surface 7116p. The locking surface 7116p, which functions as a
restricting surface, restricts the movement of the holding portion 7151Rb from
the separation holding position (first position) to the separation release position
(second position) in the ZB direction when the holding portion 7151Rb is placed
at the separation holding position (first position).
[1564] As shown in Figure 338, when the separation control member 7196R is
placed at the home position, the movable member 6162R is placed at the
projecting position, the holding member 7151R is placed at the upper position
(first operating position), and the developing unit 7109 is placed at the separated
position. The developing unit 7109 is urged in the VI direction by the moment
M30 produced by the development separation spring (not shown), and therefore,
the separated position is stably maintained.
[1565] As described above, when the movable member 6162R is placed at the
standby position, the holding member 7151R is placed at the standby position
shown in Figure 328. Also, as shown in Figures 332 to 338, when the movable
member 6162R is in the projecting position, the holding member 7151R can take
the lower position (second operating position) or the upper position (first
operating position). When the holding member 715IR is in the lower position
(second operating position), the developing unit 7109 is in the contact position,
and when the holding member 7151R is in the upper position (first operating
position), the developing unit 7109 is in the separated position.
[1566] In other words, the holding member 7151R, which includes the
separating force receiving surface 7151Rh as a separating force receiving portion,
is capable of taking the standby position, the upper position (firstoperating
position), and the lower position (second operating position) by moving in the ZB
direction, which is a predetermined direction, relative to the developing unit 7109.
The upper position (first operating position) and the lower position (second
operating position) are positions different from each other, and are positions
projecting beyond the developing unit 7109 more than that in the standby position.
In addition, it can be said that when the holding member 7151R is placed in the
standby position, the upper position (first operating position), or the lower
position (second operating position) the separating force receiving surface
7151Rh of the holding member 7151R is also placed in the standby position, the
upper position (first operating position), or the lower position (second operating
position), respectively.
[1567] Then, the holding portion 7151Rb of the holding member 7151R is
moved from the separation release position (second position) to the separation
holding position (first position) by the separating force receiving surface 7151Rh
receiving a separating force from the separation control member 7196R and
moving in the -ZB direction (predetermined direction) to the upper position (first
operating position) from the position in the state in which the developing unit
7109 is in the contact position (development position), the holding portion
7151Rb is in the separation release position (second position), and the separating
force receiving surface 7151Rh is in a lower position (second operating position).
The predetermined direction includes the ZB direction and the -ZB direction.
[1568] The above-described contact operation of the developing unit 7109 is
executed before starting printing operation, that is, when, for example, the
process cartridge 7100 is mounted in the image forming apparatus main assembly
170 and a command to start printing is outputted to the image forming apparatus
M. Then, the printing operation is started with the developing unit 7109
positioned at the contact position (the state shown in Figure 335).
[1569] After printing is completed, the separating operation of developing unit
7109 is carried out. When the developing unit 7109 is in the separated position
(the state shown in Figure 338), the image forming apparatus M is in the standby
state. When the image forming apparatus M is in the standby state and the
command to start printing is outputted to the image forming apparatus M, the
contact operation of the developing unit 7109 is carried out as described above.
<Modification of Embodiment 33>
[1570] Next, referring to Figure 339 to part (b) of Figure 343, modified
examples of Embodiment 33 will be described. Figure 339 is an illustration of a
state similar to that of Figure 338, in which the developing unit 7109 is in the
separated position and the separation control member 7196R is in the home position. Figure 340 is an illustration of a state similar to that of Figure 336, in which the developing unit 7109 is in the position and the separation control member 7196R is about to move in the W41 direction. Figure 339 and 340 are illustrations for explaining the task with Embodiment 33, and are not illustrations showing a modified example of Embodiment 33.
[1571] Figure 341 is a perspective view illustrating a drive side cartridge
cover member 8116 related to a modified example of Embodiment 33. Part (a)
of Figure 342 is an illustration of a modified example of Embodiment 33, in
which the developing unit 7109 is in the separated position and the separation
control member 7196R is in the home position. Part (b) of Figure 342 is an
enlarged view illustrating the neighborhood of the support portion 8116s in the
state shown in part (a) of Figure 342. Part (a) of Figure 343 is an illustration of
the modified example of Embodiment 33, in which the developing unit 7109 is in
the contact position and the separation control member 7196R is about to move in
the W41 direction. Part (b) of Figure 343 is an enlarged view illustrating the
neighborhood of the support portion 8116s in the state shown in part (a) of Figure
343.
[1572] As shown in Figure 339, in Embodiment 33, the holding member
7151R receives an urging force F31 of the compression spring 6153R.
Therefore, the locking surface 7 1 16p of the drive side cartridge cover member
7116 receives the urging force F31 from the holding portion 7151Rb. At this
time, depending on the strength of the urging force F31 and the stiffness of the
elastic portion 7116n, the elastic portion 7116n is elastically deformed in the V31
direction about abase portion 7116u thereof by the urging force F31. Ifthe
amount of deformation of the elastic portion 7116n in the V31 direction is large,
the holding portion 7151Rb of the holding member 7151R may disengage off the
locking surface 7116p, and the developing unit 7109 may not be able to perform the separating operation or the contact operation properly.
[1573] Also, as shown in Figure 340, in Embodiment 33, the force F41 which
the separating force receiving surface 7151Rh of the holding member 7151R
receives from the second force applying surface 7196Rb of the separation control
member 7196R can be decomposed into a component force F41a and a
component force F41b. The component force F41b is a force in the -ZB
direction. The force component F41a is a force in the XB direction
perpendicular to the -ZB direction, and includes a component in a direction of
swinging the developing unit 7109 toward the separated position.
[1574] When the urging force F31 of the compression spring 6153R is greater
than the component force F41b, the holding member 7151R is not moved in the
ZB direction by the component force F41b, and the developing unit 7109 tends to
swing in the VI direction by the component force F41a. In this case, the contact
portion 7151Rc of the holding member 7151R applies a force F141a resulting
from the component force F41a to the contacted surface 7116q, and tends to
move in the -ZB direction along the contacted surface 7116q. However, if the
stiffness of the elastic portion 7116n is not enough, the contacted surface 7116q
will deform in the V31 direction while the holding member 7151R is kept from
moving in the -ZB direction, and the holding portion 7151Rb will not be able to
move to the separation holding position (first position).
[1575] Therefore, in the modified example of Embodiment 33, as shown in
Figure 341, a support portion 8116s is provided on the drive side cartridge cover
member 8116. The drive side cartridge cover member 8116 has a structure in
which the support portion 8116s is added to the structure of the drive side
cartridge cover member 7116 of Embodiment 33, and therefore has a
development urging portion 7116s similar to Embodiment 33.
[1576] The support portion 8116s has an arm portion 8116n formed along the elastic portion 7116n, an upper surface 8116p, and an inclined surface 8116q.
The arm portion 8116n is structured to have higher stiffness than the elastic
portion 7116n. The upper surface 8 1 16p is formed flush with the locking
surface 7 1 1 6 p, and is formed of a surface that is parallel to the -XB direction or
that faces in the -ZB direction as it goes in the -XB direction. The inclined
surface 8116q inclines in the XB direction as goes in the -ZB direction, and
generally faces in the -XB direction. The upper surface 8 1 16p and the inclined
surface 8116q are disposed downstream, in the V31 direction, of the contacted
surface7116q. The contact portion 7151Rc of the holding member 7151R
overlaps the locking surface 7 1 1 6 p, the contacted surface 7116q, the upper
surface 8 1 1 6 p, and the inclined surface 8116q in the rotational axis direction of
the photosensitive drum 104 (Y1 direction and Y2 direction).
[1577] As shown in part (a) of Figure 342 and part (b) of Figure 342, in the
state where the developing unit 7109 is in the separated position and the
separation control member 7196R is in the home position, the upper surface 8 1 16p of the drive side cartridge cover member 8116 receives the urging force
F31 of the compression spring 6153R (see Figure 339, not shown in part (a) of
Figure 342 and part (b) of Figure 342) from the holding portion 7151Rb. The
arm portion 8116n formed continuous to the upper surface 8 1 16 p has higher
stiffness than the elastic portion 7116n and is therefore not elastically deformed
in the V31 direction. In addition, since the upper surface 8 1 16 p receives the
urging force F31, the elastic portion 7116n does not receive a force sufficient to
elastically deform in the V31 direction. By this, the holding portion 7151Rb of
the holding member 7151R is prevented from disengaging off the locking surface
7116p.
[1578] As shown in part (a) of Figure 343 and part (b) of Figure 343, when the
developing unit 7109 is in the contact position and the separation control member
7196R is about to move in the W41 direction, even if the developing unit 7109
swings toward the separation position due to the component force F41a, the
inclined surface 8116q will be subjected to a force F141a resulting from the
component force F41a when the contact portion 7151Rc of the holding member
7151R abuts against the inclined surface 8116q. The arm portion 8116n formed
continuously from the inclined surface 8116q by way of the upper surface 8 1 16 p
has higher stiffness than the elastic portion 7116n, and therefore does not
elastically deform in the V31 direction. Therefore, the contacted surface 7116q
does not move in the V31 direction beyond the position of the inclined surface
8116q. That is, the support portion 8116s receives a force from the holding
portion 7151Rb, thereby preventing the elastic deformation of the development
urging portion 7116s from exceeding a predetermined amount. Therefore, the
holding member 7151R can be reliably moved in the -ZB direction by the
component force F41b, and the contact operation and separating operation can be
performed appropriately.
[1579] Although the above description is about the drive side, the
separation/contact mechanism (7150L) is also provided on the non-drive side.
By this, the same operation can be performed on the non-drive side as well. By
performing separation and contact operations on both the drive side and the non
drive side, the developing unit 7109 can be swung about the swing axis K reliably
and stably.
[1580] According to the structure of this embodiment described above, the
same effects as those of Embodiment 1 can be obtained. In addition, in this
embodiment, the developing unit 7109 to be switched between an contact
position and a separated position by, the holding member 7151R moving only in
the ZB direction (and the -ZB direction), and therefore, the space required to
position the holding member 7151R can be reduced, and the process cartridge
7100 can be downsized.
[1581] In addition, in this embodiment, the holding portion 7151Rb and the free end portion 7151Rm are integrally provided on the holding member 7151R,
but this not inevitable in the present invention. For example, the holding portion 7151Rb may be provided separately from the free end portion 7151Rm, and the
holding portion 7151Rb may be structured to be movable between the first
position (separation holding position) and the second position (separation release
position) in interrelation with the free end portion 7151Rm moved by the
separation control member 7196R. In addition, in this embodiment, the holding
member 7151R is supported by the development cover member 6128 of the
developing unit 7109, but the present invention is not limited to such an example.
For example, the holding member 7151R may be movably supported by the drum
unit 108, or may be supported by the movable member 6162R.
[1582] In this embodiment, the developing unit 7109 is urged toward the contact position (developing position) by the development urging portion 7116s
including the elastic portion 7116n formed of a leaf spring or the like, but the
present invention is not limited to such an example. For example, the
developing unit 7109 may be urged toward the contact position (developing
position) by way of the holding portion 7151Rb using an elastic member such as a torsion coil spring, rubber, or sponge. The material of the elastic portion
7116n may be any material such as metal or mold.
[1583] Moreover, Embodiment 33 may be appropriately combined with one or more of the previously described Embodiments 1 to 32.
[1584] The disclosure of this embodiment also includes the following structures and methods.
(Structure Al).
[1585] A cartridge comprising: a first unit including a photosensitive member, and a first frame rotatably supporting the photosensitive member; a second unit including a developing member for depositing toner onto the photosensitive member, and a second frame rotatably supporting the developing member, wherein the second unit is movable relative to the first unit between a developing position in which toner can be deposited onto the photosensitive member from the developing member, and a separated position in which at least a part of the developing member is spaced from the photosensitive member; a holding portion, movably supported by the first unit or the second unit, for restricting a relative position between the first unit and the second unit, wherein the holding portion is movable between a first position for holding the second unit at the separated position by the first unit and a second position for holding the second unit at the developing position by the first unit; and a contact force receiving portion movably supported by the first frame or the second frame and capable of receiving a contact force for moving the holding portion from the first position toward the second position to move the second unit to the developing position when the second unit is at the separated position, wherein the contact force receiving portion is capable of taking, by moving relative to the second frame in a predetermined direction, (i) a stand-by position,
(ii) a first operating position more outward beyond the second frame than in the
stand-by position, and (iii) a second operating position which is more outward
beyond the second frame than in the stand-by position and which is different
from the first operating position with respect to the predetermined direction, and
wherein the holding portion is moved from the first position to the second
position, by the contact force receiving portion receiving the contact force and
moving to the second operating position in the predetermined direction, in a state
in which the second unit is in the separated position, the holding portion is in the first position, and the contact force receiving portion is in the first operating position.
(Structure A2)
[1586] According to Structure Al, wherein the contact force receiving portion
has an inclined surface inclined relative to the predetermined direction, and as
viewed in a rotational axis of the photosensitive member, the inclined surface
inclines away from the rotational axis as goes approaching the rotational axis in a
direction perpendicular to the predetermined direction.
(Structure A3)
[1587] According to Structure Al or A2, wherein the holding portion is
capable of restricting, when it is at the first position, movement of the second unit
from the separated position to the developing position, and permits, when the
holding portion is at the second position, movement of the second unit from the
separated position to the developing position.
(Structure A4)
[1588] According to Structure A3, wherein the holding portion restricts, when
it is at the first position, movement of the second unit from the separated position
to the developing position by contact with the first frame and with the second
frame.
(Structure A5)
[1589] According to any one of Structures Al - A4, further comprising an
urging portion for urging the second unit toward the developing position.
(Structure A6)
[1590] According to any one of Structures Al - A5, further comprising a
holding member including the holding portion and the contact force receiving
portion and supported by the second frame movably in the predetermined
direction.
(Structure A7)
[1591] According to Structure A6, wherein the holding member is provided
with a separating force receiving portion capable of receiving a separating force
for moving the holding portion from the second position toward the first position
to move the second unit to the separated position.
(Structure A8)
[1592] According to Structure A7, wherein the movable member is provided
with a projected portion capable of projecting out beyond the first frame and the
second frame at least in a direction away from a rotational axis of the developing
member, and the contact force receiving portion and the separating force
receiving portion are provided on the projected portion.
(Structure A9)
[1593] According to Structure A7 or A8, wherein the second unit is provided
with a first restriction surface for restricting movement of the holding portion in a
direction opposite to the direction from the second position toward the first
position with respect to the predetermined direction, when the separating force
receiving portion receives the separating force.
(Structure A10)
[1594] According to any one of Structures A6 - A9, wherein the second unit is
provided with a movable member supported by the second frame so as to be
movable in the predetermined direction, and a holding member urging portion for
urging the holding member toward the movable member so as to move the
contact force receiving portion away from the rotational axis of the developing
member in the predetermined direction.
(Structure Al l)
[1595] According to any one of Structures Al - AlO, wherein the first frame
has a second restriction surface for restricting movement of the holding portion from the second position to the first position with respect to the predetermined direction, when the holding portion is in the second position.
(Structure B1)
[1596] A cartridge comprising:
a first unit including a photosensitive member, and a first frame rotatably
supporting the photosensitive member;
a second unit including a developing member for depositing toner onto the
photosensitive member, and a second frame rotatably supporting the developing
member, wherein the second unit is movable relative to the first unit between a
developing position in which toner can be deposited onto the photosensitive
member from the developing member, and a separated position in which at least a
part of the developing member is spaced from the photosensitive member;
a holding portion, movably supported by the first unit or the second unit,
for restricting a relative position between the first unit and the second unit,
wherein the holding portion is movable between a first position for holding the
second unit at the separated position by the first unit and a second position for
holding the second unit at the developing position by the first unit; and
a separating force receiving portion movably supported by the first frame
or the second frame capable of receiving a separating force force for moving the
holding portion from the second position toward the first position to move the
second unit to the separated position when the second unit is at the developing
position,
wherein the separating force receiving portion is capable of taking, by
moving relative to the second frame in a predetermined direction, (i) a stand-by
position, (ii) a first operating position which is more outward beyond the second
frame than in the stand-by position, and (iii) a second operating position more
outward beyond the second frame than in the stand-by position and which is different from the first operating position with respect to the predetermined direction, and wherein the holding portion is moved from the second position to the first position, by the separating force receiving portion receiving the separating force and moving to the first operating position in the predetermined direction, in a state in which the second unit is in the developing position, the holding portion is in the second position, and the separating force receiving portion is in the second operating position.
(Structure B2)
[1597] According to Structure B1, wherein the separating force receiving
portion has an inclined surface inclined relative to the predetermined direction,
and as viewed in a rotational axis of the photosensitive member, the inclined
surface inclines approaching the rotational axis as goes approaching the rotational
axis in a direction perpendicular to the predetermined direction.
(Structure B3)
[1598] According to Structure B Ior B2, further comprising an urging portion
for urging the second unit toward the separated position.
(Structure B4)
[1599] According to any one of Structures B I- B3, wherein the first frame or
the second frame includes a development urging portion capable of urging the
second unit toward the developing position by pressing the holding portion.
(Structure B5)
[1600] According to Structure B4, wherein the development urging portion
presses the holding portion so as to move the second unit toward the developing
position, by elastic deformation when the holding portion moves from the first
position to the second position.
(Structure B6)
[1601] According to Structure B4 or B5, wherein the holding portion is
provided with a contact portion pressed by the development urging portion when
the holding portion is at the second position. (Structure B7)
[1602] According to any one of Structures B4 - B6, wherein the holding
portion is supported by the second frame so as to be movable in the
predetermined direction, and the development urging portion is provided on the
first frame.
(Structure B8)
[1603] According to Structure B7, wherein the first frame is provided with a
support portion for restricting elastic deformation of the development urging
portion beyond a predetermined amount by receiving a force from the holding
portion.
(Structure B9)
[1604] According to any one of Structures BI - B8, further comprising a
holding member including the holding portion and the separating force receiving
portion, the holding member being supported so as to be movable by the second
frame in the predetermined direction.
(Structure B10)
[1605] According to Structure B9, wherein the holding member is provided
with a contact force receiving portion capable of receiving the contact force for
moving the holding portion from the first position toward the second position to
move the second unit to the developing position.
(Structure B11)
[1606] According to Structure B10, wherein the movable member is provided
with a projected portion capable of projecting out beyond the first frame and the
second frame at least in a direction away from a rotational axis of the developing
member, and the contact force receiving portion and the separating force receiving portion are provided on the projected portion.
(Structure B12)
[1607] According to any one of Structures B9 - B11, wherein the second unit
is provided with a movable member supported by the second frame so as to be
movable in the predetermined direction, and a holding member urging portion for
urging the holding member toward the movable member so as to move the
separating force receiving portion away from the rotational axis of the developing
member in the predetermined direction.
(Structure B13)
[1608] According to any one of Structures B I- B12, wherein the first frame
has a restriction surface for restricting movement of the holding portion from the
first position to the second position with respect to the predetermined direction,
when the holding portion is in the first position.
(Structure C1)
[1609] An image forming apparatus comprising, a cartridge according to any
one of Structures Al - B13; and a main assembly to which the cartridge is
mountable.
[1610] A cartridge and an electrophotographic image forming apparatus are
provided which include a first unit including a photosensitive member, and a
second unit including a developing member for depositing toner onto the
photosensitive member and movable between a developing position and a
separated position.
[1611] The present invention is not limited to the above-described
embodiments, and various modifications and variations are possible without
departing from the spirit and scope of the present invention. Therefore, to publicize the scope of the invention, the following claims are attached.
[1612] This application claims priority based on Japanese Patent Application
No. 2022-093445 filed on June 9, 2022, the entire contents of which are
incorporated herein by reference.
Claims (25)
- Claim 1. A cartridge comprising:a first unit including a photosensitive member, and a first frame rotatablysupporting the photosensitive member;a second unit including a developing member for depositing toner onto thephotosensitive member, and a second frame rotatably supporting the developingmember, wherein the second unit is movable relative to the first unit between adeveloping position in which toner can be deposited onto the photosensitivemember from the developing member, and a separated position in which at least apart of the developing member is spaced from the photosensitive member;a holding portion, movably supported by the first unit or the second unit,for restricting a relative position between the first unit and the second unit,wherein the holding portion is movable between a first position for holding thesecond unit at the separated position by the first unit and a second position forholding the second unit at the developing position by the first unit; anda contact force receiving portion movably supported by the first frame orthe second frame and capable of receiving a contact force for moving the holdingportion from the first position toward the second position to move the second unitto the developing position when the second unit is at the separated position,wherein the contact force receiving portion is capable of taking, by movingrelative to the second frame in a predetermined direction, (i) a stand-by position,(ii) a first operating position more outward beyond the second frame than in thestand-by position, and (iii) a second operating position which is more outwardbeyond the second frame than in the stand-by position and of which a position tothe second frame is different from a position of the first operating position with respect to the predetermined direction, and wherein the holding portion is moved from the first position to the second position, by the contact force receiving portion receiving the contact force and moving to the second operating position in the predetermined direction, in a state in which the second unit is in the separated position, the holding portion is in the first position, and the contact force receiving portion is in the first operating position.
- Claim 2. A cartridge according to Claim 1, wherein the contact forcereceiving portion has an inclined surface inclined relative to the predetermineddirection, and as viewed in a rotational axis of the photosensitive member, theinclined surface inclines away from the rotational axis as goes approaching therotational axis in a direction perpendicular to the predetermined direction.
- Claim 3. A cartridge according to Claim 1, wherein the holding portionis capable of restricting, when it is at the first position, movement of the secondunit from the separated position to the developing position, and permits, when theholding portion is at the second position, movement of the second unit from theseparated position to the developing position.
- Claim 4. A cartridge according to Claim 3, wherein the holding portionrestricts, when it is at the first position, movement of the second unit from theseparated position to the developing position by contact with the first frame andwith the second frame.
- Claim 5. A cartridge according to Claim 1, further comprising an urgingportion for urging the second unit toward the developing position.
- Claim 6. A cartridge according to Claim 1, further comprising a holdingmember including the holding portion and the contact force receiving portion andsupported by the second frame movably in the predetermined direction.
- Claim 7. A cartridge according to Claim 6, wherein the holding memberis provided with a separating force receiving portion capable of receiving aseparating force for moving the holding portion from the second position towardthe first position to move the second unit to the separated position.
- Claim 8. A cartridge according to Claim 7, wherein the movablemember is provided with a projected portion capable of projecting out beyond thefirst frame and the second frame at least in a direction away from a rotational axisof the developing member, and the contact force receiving portion and theseparating force receiving portion are provided on the projected portion.
- Claim 9. A cartridge according to Claim 7, wherein the second unit isprovided with a first restriction surface for restricting movement of the holdingportion in a direction opposite to the direction from the second position towardthe first position with respect to the predetermined direction, when the separatingforce receiving portion receives the separating force.
- Claim 10. A cartridge according to Claim 6, wherein the second unit isprovided with a movable member supported by the second frame so as to bemovable in the predetermined direction, and a holding member urging portion forurging the holding member toward the movable member so as to move thecontact force receiving portion away from the rotational axis of the developing member in the predetermined direction.
- Claim 11. A cartridge according to Claim 1, wherein the first frame hasa second restriction surface for restricting movement of the holding portion fromthe second position to the first position with respect to the predetermineddirection, when the holding portion is in the second position.
- Claim 12. A cartridge comprising: a first unit including a photosensitive member, and a first frame rotatablysupporting the photosensitive member;a second unit including a developing member for depositing toner onto thephotosensitive member, and a second frame rotatably supporting the developingmember, wherein the second unit is movable relative to the first unit between adeveloping position in which toner can be deposited onto the photosensitivemember from the developing member, and a separated position in which at least a part of the developing member is spaced from the photosensitive member;a holding portion, movably supported by the first unit or the second unit,for restricting a relative position between the first unit and the second unit,wherein the holding portion is movable between a first position for holding thesecond unit at the separated position by the first unit and a second position forholding the second unit at the developing position by the first unit; anda separating force receiving portion movably supported by the first frameor the second frame capable of receiving a separating force force for moving theholding portion from the second position toward the first position to move thesecond unit to the separated position when the second unit is at the developingposition,wherein the separating force receiving portion is capable of taking, by moving relative to the second frame in a predetermined direction, (i) a stand-by position, (ii) a first operating position more outward beyond the second frame than in the stand-by position, and (iii) a second operating position which is more outward beyond the second frame than in the stand-by position and of which a position to the second frame is different from a position of the first operating position with respect to the predetermined direction, and wherein the holding portion is moved from the second position to the first position, by the separating force receiving portion receiving the separating force and moving to the first operating position in the predetermined direction, in a state in which the second unit is in the developing position, the holding portion is in the second position, and the separating force receiving portion is in the second operating position.
- Claim 13. A cartridge according to Claim 12, wherein the separatingforce receiving portion has an inclined surface inclined relative to the predetermined direction, and as viewed in a rotational axis of the photosensitivemember, the inclined surface inclines approaching the rotational axis in thepredetermined direction as goes approaching the rotational axis in a directionperpendicular to the predetermined direction.
- Claim 14. A cartridge according to Claim 12, further comprising anurging portion for urging the second unit toward the separated position.
- Claim 15. A cartridge according to Claim 12, wherein the first frame orthe second frame includes a development urging portion capable of urging thesecond unit toward the developing position by pressing the holding portion.
- Claim 16. A cartridge according to Claim 15, wherein the developmenturging portion presses the holding portion so as to move the second unit towardthe developing position, by elastic deformation when the holding portion movesfrom the first position to the second position.
- Claim 17. A cartridge according to Claim 15, wherein the holdingportion is provided with a contact portion pressed by the development urgingportion when the holding portion is at the second position.
- Claim 18. A cartridge according to Claim 15, wherein the holdingportion is supported by the second frame so as to be movable in thepredetermined direction, and the development urging portion is provided on thefirst frame.
- Claim 19. A cartridge according to Claim 18, wherein the first frame isprovided with a support portion for restricting elastic deformation of thedevelopment urging portion beyond a predetermined amount by receiving a forcefrom the holding portion.
- Claim 20. A cartridge according to Claim 12, further comprising aholding member including the holding portion and the separating force receivingportion, the holding member being supported so as to be movable by the secondframe in the predetermined direction.
- Claim 21. A cartridge according to Claim 20, wherein the holdingmember is provided with a contact force receiving portion capable of receivingthe contact force for moving the holding portion from the first position toward the second position to move the second unit to the developing position.
- Claim 22. A cartridge according to Claim 21, wherein the movablemember is provided with a projected portion capable of projecting out beyond thefirst frame and the second frame at least in a direction away from a rotational axisof the developing member, and the contact force receiving portion and theseparating force receiving portion are provided on the projected portion.
- Claim 23. A cartridge according to Claim 20, wherein the second unit isprovided with a movable member supported by the second frame so as to bemovable in the predetermined direction, and a holding member urging portion forurging the holding member toward the movable member so as to move theseparating force receiving portion away from the rotational axis of the developingmember in the predetermined direction.
- Claim 24. A cartridge according to Claim 12, wherein the first framehas a restriction surface for restricting movement of the holding portion from thefirst position to the second position with respect to the predetermined direction,when the holding portion is in the first position.
- Claim 25. An image forming apparatus comprising, a cartridgeaccording to Claim 1; and a main assembly to which the cartridge is mountable.Claim 1. (After Amendment) A cartridge comprising:a first unit including a photosensitive member, and a first frame rotatablysupporting the photosensitive member;a second unit including a developing member for depositing toner onto thephotosensitive member, and a second frame rotatably supporting the developingmember, wherein the second unit is movable relative to the first unit between adeveloping position in which toner can be deposited onto the photosensitivemember from the developing member, and a separated position in which at least apart of the developing member is spaced from the photosensitive member;a holding portion, movably supported by the first unit or the second unit,for restricting a relative position between the first unit and the second unit,wherein the holding portion is movable between a first position for holding thesecond unit at the separated position by the first unit and a second position forholding the second unit at the developing position by the first unit; anda contact force receiving portion movably supported by the first frame orthe second frame and capable of receiving a contact force for moving the holdingportion from the first position toward the second position to move the second unitto the developing position when the second unit is at the separated position,wherein the contact force receiving portion is capable of taking, by movingrelative to the second frame in a predetermined direction, (i) a stand-by position,(ii) a first operating position more outward beyond the second frame than in thestand-by position, and (iii) a second operating position which is more outwardbeyond the second frame than in the stand-by position and of which a position tothe second frame is different from a position of the first operating position with respect to the predetermined direction, and wherein the holding portion is moved from the first position to the second position, by the contact force receiving portion receiving the contact force and moving to the second operating position in the predetermined direction, in a state in which the second unit is in the separated position, the holding portion is in the first position, and the contact force receiving portion is in the first operating position.Claim 2. A cartridge according to Claim 1, wherein the contact forcereceiving portion has an inclined surface inclined relative to the predetermineddirection, and as viewed in a rotational axis of the photosensitive member, theinclined surface inclines away from the rotational axis as goes approaching therotational axis in a direction perpendicular to the predetermined direction.Claim 3. A cartridge according to Claim 1, wherein the holding portionis capable of restricting, when it is at the first position, movement of the secondunit from the separated position to the developing position, and permits, when theholding portion is at the second position, movement of the second unit from theseparated position to the developing position.Claim 4. A cartridge according to Claim 3, wherein the holding portionrestricts, when it is at the first position, movement of the second unit from theseparated position to the developing position by contact with the first frame andwith the second frame.Claim 5. A cartridge according to Claim 1, further comprising an urgingportion for urging the second unit toward the developing position.Claim 6. A cartridge according to Claim 1, further comprising a holdingmember including the holding portion and the contact force receiving portion andsupported by the second frame movably in the predetermined direction.Claim 7. A cartridge according to Claim 6, wherein the holding memberis provided with a separating force receiving portion capable of receiving aseparating force for moving the holding portion from the second position towardthe first position to move the second unit to the separated position.Claim 8. A cartridge according to Claim 7, wherein the movablemember is provided with a projected portion capable of projecting out beyond thefirst frame and the second frame at least in a direction away from a rotational axisof the developing member, and the contact force receiving portion and theseparating force receiving portion are provided on the projected portion.Claim 9. A cartridge according to Claim 7, wherein the second unit isprovided with a first restriction surface for restricting movement of the holdingportion in a direction opposite to the direction from the second position towardthe first position with respect to the predetermined direction, when the separatingforce receiving portion receives the separating force.Claim 10. A cartridge according to Claim 6, wherein the second unit isprovided with a movable member supported by the second frame so as to bemovable in the predetermined direction, and a holding member urging portion forurging the holding member toward the movable member so as to move thecontact force receiving portion away from the rotational axis of the developing member in the predetermined direction.Claim 11. A cartridge according to Claim 1, wherein the first frame hasa second restriction surface for restricting movement of the holding portion fromthe second position to the first position with respect to the predetermineddirection, when the holding portion is in the second position.Claim 12. (After Amendment) A cartridge comprising:a first unit including a photosensitive member, and afirst frame rotatablysupporting the photosensitive member;a second unit including a developing member for depositing toner onto thephotosensitive member, and a second frame rotatably supporting the developingmember, wherein the second unit is movable relative to the first unit between adeveloping position in which toner can be deposited onto the photosensitivemember from the developing member, and a separated position in which at least a part of the developing member is spaced from the photosensitive member;a holding portion, movably supported by the first unit or the second unit,for restricting a relative position between the first unit and the second unit,wherein the holding portion is movable between a first position for holding thesecond unit at the separated position by the first unit and a second position forholding the second unit at the developing position by the first unit; anda separating force receiving portion movably supported by the first frameor the second frame capable of receiving a separating force force for moving theholding portion from the second position toward the first position to move thesecond unit to the separated position when the second unit is at the developing position,wherein the separating force receiving portion is capable of taking, by moving relative to the second frame in a predetermined direction, (i) a stand-by position, (ii) a first operating position more outward beyond the second frame than in the stand-by position, and (iii) a second operating position which is more outward beyond the second frame than in the stand-by position and of which a position to the second frame is different from a position of the first operating position with respect to the predetermined direction, and wherein the holding portion is moved from the second position to the first position, by the separating force receiving portion receiving the separating force and moving to the first operating position in the predetermined direction, in a state in which the second unit is in the developing position, the holding portion is in the second position, and the separating force receiving portion is in the second operating position.Claim 13. A cartridge according to Claim 12, wherein the separatingforce receiving portion has an inclined surface inclined relative to thepredetermined direction, and as viewed in a rotational axis of the photosensitivemember, the inclined surface inclines approaching the rotational axis in thepredetermined direction as goes approaching the rotational axis in a directionperpendicular to the predetermined direction.Claim 14. A cartridge according to Claim 12, further comprising anurging portion for urging the second unit toward the separated position.Claim 15. A cartridge according to Claim 12, wherein the first frame orthe second frame includes a development urging portion capable of urging the second unit toward the developing position by pressing the holding portion.Claim 16. A cartridge according to Claim 15, wherein the developmenturging portion presses the holding portion so as to move the second unit towardthe developing position, by elastic deformation when the holding portion movesfrom the first position to the second position.Claim 17. A cartridge according to Claim 15, wherein the holdingportion is provided with a contact portion pressed by the development urgingportion when the holding portion is at the second position.Claim 18. A cartridge according to Claim 15, wherein the holdingportion is supported by the second frame so as to be movable in thepredetermined direction, and the development urging portion is provided on thefirst frame.Claim 19. A cartridge according to Claim 18, wherein the first frame isprovided with a support portion for restricting elastic deformation of thedevelopment urging portion beyond a predetermined amount by receiving a forcefrom the holding portion.Claim 20. A cartridge according to Claim 12, further comprising aholding member including the holding portion and the separating force receivingportion, the holding member being supported so as to be movable by the secondframe in the predetermined direction.Claim 21. A cartridge according to Claim 20, wherein the holdingmember is provided with a contact force receiving portion capable of receivingthe contact force for moving the holding portion from the first position toward the second position to move the second unit to the developing position.Claim 22. A cartridge according to Claim 21, wherein the movablemember is provided with a projected portion capable of projecting out beyond thefirst frame and the second frame at least in a direction away from a rotational axisof the developing member, and the contact force receiving portion and theseparating force receiving portion are provided on the projected portion.Claim 23. A cartridge according to Claim 20, wherein the second unit isprovided with a movable member supported by the second frame so as to bemovable in the predetermined direction, and a holding member urging portion forurging the holding member toward the movable member so as to move theseparating force receiving portion away from the rotational axis of the developingmember in the predetermined direction.Claim 24. A cartridge according to Claim 12, wherein the first framehas a restriction surface for restricting movement of the holding portion from thefirst position to the second position with respect to the predetermined direction,when the holding portion is in the first position.Claim 25. An image forming apparatus comprising, a cartridgeaccording to Claim 1; and a main assembly to which the cartridge is mountable.BRIEF STATEMENT UNDER ARTILE 19 (1)The amendment to change to "(iii) a second operating position which is more outward beyond the second frame than in the stand-by position and of which a position to the second frame is different from a position of the first operating position with respect to the predetermined direction" in claims 1 and 12 is based on a description of paragraph [1510] of the specification and is to define the second operating position so as to clarity the difference to the cited references.Fig. 1151Rc CS HC 132a 116d106 CS 151Rk 126c CS B1 H B2 153109 BB 152RnW41 152RqV2100 ZA W42 (b)152Rr152Rk108 O 151Re116c104CS151Ra 128c B2 151Rc153132a 116d CS HC 106 151 Rk CS H B1 126c152Rn152Rq109 BB W41100 ZA 0 V2 W42 (a) P1 152Rr152Rk151ReIII108116c104 CSFig. 212b 11 1064 4a170 U 100K 8 o box104M U O 100C 106 104 S 1214o 100M U U 106104 13 100Y O12d104 106 o 11712aC 4bO8 103an b 115 1167 12e 12c3 / 343100109 129125 U125b 110 108115 125a129a 130a130 130c105 130bD107 104 106 A106d 106cFig. 3X2 R 11Z1 Z2X1171 4 170M Fig. 4 8 o PABII12e OO PV1X2 100KZ1 Z2 11 100CX1100Y 100M O170 4M X2'Fig. 5o !OFX1 23 185 180 C185 180 6185 180185 18012 12a 115 O 2 4b O O 8 O o O 10312e 116 12c7 6Fig. 608100K 171a11171a100C171171a 100 100M171a100Y4M o OF180 1855180 185180 185180185 12 12a115 O 4bK O O 8 O OF 170103B116 12e 12c7 67 / 343Z1Z2100 100 116 117116KR 171KR 171KL 171 171 117KR170 009 170171VR1 171VR2 171VL2 171VL1 171VR 171VL(a) (b)Fig. 78 / 343Z1 A X1 Y2 191 Y1 X2 190 Y 100 Z26 OF195R12 195L 195 170(a)191 1001906)OD o12 170 (b) Fig. 89 / 343Z1X1 Y2 180 Y1 X2 180 185 185 Z2OPH 0 185 1112 180 180(a)180 180 185 185 180OIATH(1) 185 " B R2 R112 180 (b) Fig. 9
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022-093445 | 2022-06-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| AU2023283201A1 true AU2023283201A1 (en) | 2024-11-14 |
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